Chapter 1

 

Introduction

 

1.1. Introduction

 

Diamond is introduced as a new engineering material. Some of the outstanding properties are detailed and novel applications based on diamond materials discussed. An overview of electrochemistry using boron doped polycrystalline diamond is briefly presented. Work included in the thesis is outlined.

 

1.2. Properties of Diamond

 

Diamond has been linked with wealth, famous people, powerful politicians and rich monarchic families over many centuries. Nowadays, scientists are seeking to exploit some of the interesting properties of this allotrope of carbon (see   table 1.1).

Properties

Magnitude

Density

3.52 g cm-3

Dynamic coefficient of friction

0.03

Hardness

1´104 Kg mm-2

Compressive strength

> 100 GPa

Tensile strength

> 1.2 GPa

Thermal expansion coefficient

1´10-6 K-1

Thermal conductivity

20.0 W cm-1 K-1

Thermal shock parameter

3.0´108 Wm-1

Heat capacity

6.2 Jmol-1K-1

Optical index of refraction at 591 nm

2.41

Optical transmissivity from deep ultraviolet to far infrared

225

Electron mobility

2200 cm2V-1s-1

Hole mobility

1600 cm2V-1s-1

Electron satured velocity

2.7´10-7 cm s-1

Hole satured velocity

1.0´10-7 cm s-1

Band gap

5.45 eV

Resistivity of undoped diamond

~1016 Wcm

 

Table 1.1. Some of the properties of diamond

(values are at room temperature and pressure)

 

From the above list the following properties merit attention:

 

·        Diamond is chemically inert at room temperature and pressure. Therefore diamond is biologically compatible and could be used in sensors in biological and medical environments 1-9.

·        Diamond has an exceptional hardness that suggests it is a suitable material to be used in ultrasound technology 10-18.

 

·        Diamond is transparent over a wide spectral range, this allows optical use of diamond for different wavelength regions 19-27.

 

·        Diamond has a negative electron affinity that suggests this material can be employed as a field emitter device 28-49.

 

·        Single crystal diamond is one of the best electrical insulators but when  synthesised by the CVD technique even the undoped material is conductive 25, 50-68. Doping can be employed to further alter the charge transport properties 31-33, 51, 69-71.

 

·        Diamond has one of the highest thermal conductivity coefficients, this suggests the use of diamond as a heat sink for electronic equipment 72-77.

 

·        Diamond has a high resistivity to chemical corrosion making it an ideal material for a wide range of harsh environments 10, 78-85.

 

These properties suggest diamond as a suitable electrode material.

 

1.3. Synthesis of diamond

 

At room temperature and pressure, graphite, the sp2-bonded form of carbon, is the thermodynamically stable allotrope of carbon (see figure 1.1).

Figure 1.1. Left side structure is the sp3 diamond structure meanwhile in the right side is the sp2 graphite lattice.

 

The standard enthalpies of formation of diamond and graphite differ by only     2.9 KJ mol-1 86. However a large activation barrier separates the two phases preventing interconversion between them at room temperature and pressure. As diamond is the densest allotrope of carbon, at high pressure, diamond should be the most stable form of the solid carbon. This reasoning was the basis for the high-pressure high-temperature (HPHT) growth techniques that have been used in commercial synthesis for the last 30 years. Much effort has been spent during the 60’s and 70’s to investigate diamond growth at low pressures. Diamond synthesis was successfully achieved by Chemical Vapour Deposition (CVD) techniques at low pressures. Since the late 70’s and early 80’s when CVD was established as an economic, relatively fast and easy process for producing diamond, industrial applicationsª have been considered.

 

1.4. Commercial applications of diamond

 

Some of the commercial applications of diamond are outlined below:

 

1.4.1. Thermal applications

 

Due to the high thermal conductivity and high resistivity coefficient of diamond the material has the potential of being used as a heat sink for integrated circuits, allowing high-density packing of components whilst maintaining low operating temperatures. Some commercial laser diodes and microwave diodes include diamond as a heat sink 77, 87-93.

 

1.4.2. Electronic devices

 

The possibility of making diamond conductive, combined with its negative electron affinity has resulted in many studies aimed at producing field emitter devices 25, 32, 34, 47, 56-58, 62, 88, 94-103. Other studies have focused on light emitting devices using diamond as an electrode with specific organic solutions 104.

 

1.4.3. Optical windows

 

As table 1.1 shows diamond has a wide range of transparency from deep ultraviolet to the far infrared in the spectrum. Diamond can be used as optical material in different ranges of the light spectrum.

 

Some of the materials used for infrared imaging technology e.g. ZnSe, are too soft and require outer coatings for protection and reinforcement. Diamond emerges as an optimal material for a coating as it gives the strength and resistance ZnSe requires in the commercial device. An alternative route is the use of free standing diamond, i.e., diamond as both detector and protection 105. Free standing diamond is transparent and very resistant but it has some drawbacks, not least that it can only be deposited in planar shapes.

 

In optical applications non-planar shapes are sometimes required. As was pointed out diamond is very hard and polishing to form lenses is never an easy task. It should also be noted that for some specific optical applications the contamination (by traces of metal in the heating elements of the growth chamber or impurities in the gases used in the synthesis mixture, etc) of the free standing diamond could make it unsuitable material.  

 

1.4.4. Abrasives

 

For more than 30 years diamond has been used as a material to abrade, cut and polish. Mainly it has been applied in heavy duty machinery in industry to cut, drill and polish materials. Nowadays as the price of diamond synthesis has decreased it is being used in less demanding environments as protective material in gloves and clothes and in specific surgery material like dental drills and scalpels 106, 107-108.

 

1.5. Electrochemistry of diamond

 

The first paper on the electrochemistry of boron doped polycrystalline diamond was published by Pleskov et al. in 1987 109. The demonstration of the possibility of performing electrochemistry on polycrystalline diamond resulted in considerable interest in electrodes fabricated from this new material. Three advantages of diamond electrodes were identified. First, it was demonstrated that diamond electrodes have a large potential window in aqueous solution with low background currents 4-8, 10-18, 20, 21, 78, 82, 85, 88, 110-145. Second, it was shown that electrodes formed from polycrystalline diamond possess physical properties similar to those of bulk diamond 71, 146-150, including: hardness, low environmental impact, high hole mobility, high thermal conductivity and excellent resistance to radiation damage. Third, the surface is stable and there is little evidence of degradation of electrochemical activity with time 16, 70, 110, 151-160. These characteristics of diamond electrodes have been employed in a number of applications.

 

1.5.1. Electrochemical applications of diamond

 

 It has been demonstrated that the wide potential window at diamond electrodes can be used in the generation of ammonia from aqueous nitrate solutions 83, 85. The mechanical strength of diamond electrodes has resulted in them being utilised in sonoelectrochemical experiments 10-18, 114, 118. Whilst, the resistance to fouling has resulted in diamond being a material of choice for electroanalytical studies 2, 4-8, 10-18, 20, 21, 70, 78, 79, 84, 88, 110-126, 128-131, 133, 135, 137, 140, 142-145, 151-156, 158, 159, 161-172. Addition to the electroanalytical applications diamond electrodes has been used in the treatment of polluted water 4, 13, 14, 17, 110, 112, 115, 116, 118, 121, 123, 129, 131, 151-156, 158, 159 and in the precise detection of contaminants in the environment 4, 13, 14, 17, 21, 78, 110-116, 118, 120, 121, 123, 129, 131, 162, 165, 166, 169, 171, 173, food industry 4, 111, 113, 123 and pharmaceutical industry 2, 5, 7, 8, 113, 123-125, 129, 163.

 

1.5.2. Electrochemical studies of highly boron doped diamond in aqueous media

 

Most electrochemical studies of diamond have been performed on highly boron doped, p-type, material in aqueous solvents. It has been shown that for simple redox couples in aqueous solution the electrochemical response at a diamond electrode resembles that of a metal electrode 5, 6, 78, 88, 115, 116, 123, 126, 174. Further, it has been illustrated that the rate of electron transfer reactions is dependent up on whether the surface is hydrogen or oxygen terminated 143, 175. It has been suggested that the valance band edge at hydrogen terminated diamond electrode lies at a greater energy than the aqueous H+/H2 couple, this would result in hydrogen terminated diamond always being in accumulation when in an aqueous electrolyte 176. Thus any applied potential would be dropped across the Helmholtz layer and reversible electrochemical behaviour observed for simple redox couples. Indeed an accumulation of holes at a hydrogen terminated diamond surface exposed to the atmosphere has been used to explain the enhanced surface conductivity of the material 3, 25, 32, 39, 43, 46, 49, 51, 53, 58, 117, 122, 177-181. At an oxygen terminated diamond surface reversible electron transfer occurs at potentials at which Mott-Schottky analysis suggests the surface is in depletion. Impedance studies 175, 176 indicate that electron transfer at an oxygen terminated diamond surface occurs via surface states 143, 175, 176. It has been postulated that sp2 carbon surface impurities mediate the charge transfer.

 

1.5.3. Electrochemical studies of highly boron doped diamond in non- aqueous media

 

Studies of diamond electrodes in non-aqueous electrolytes are more limited. It has been reported that diamond electrodes in non-aqueous electrolyte posses an increased potential window, allowing a fifth peak for the reduction of C60 to be observed 135. In addition diamond electrodes have been employed in the generation of solvated electrons in ammonia 79.

 

1.5.4. Electrochemical studies of moderately boron doped diamond in aqueous media

 

Studies of moderatly boron doped diamond electrodes are limited. Pleskov et al.182, 183 using suprabandgap illumination have performed inconclusive studies on the semiconducting properties of diamond. Rao et al. 184 using the same system undertook photocurrent measurements from suprabandgap illumination. The results show some interesting current-voltage responses for semiconductor  diamond but Mott-Schottky plots locating the flat band potential are not precise. If the flat band potential is placed as they suggest at approximately at +4.6 eV vs standard hydrogen electrode (SHE) the surfaces should exhibit negative electron affinity (nea). However nea is observed only at specially pre-treated surfaces 185 or nitrogen doped diamond 186. Moreover if the flat band is situated as Rao et al. propose exchange of the electron for an standard redox couple as ferrocyanide/ferricyanide redox couple should be slow. However a high exchange range at equilibrium and reversible kinetics are observed 84, 141, 143, 144, 187.

 

1.5.5. Electrochemical studies of undoped diamond in aqueous media

 

Studies of undoped diamond electrodes are limited. Shakarova et al. 50, Zhang et al. 188, Rohrer et al. 59, Nebel et al. 65 and Pereira et al. 66 have performed photoconductivity experiments to determine the energy bands in undoped diamond and its electrical properties. Grain boundaries have been shown to play an important role in the conductivity mechanism. Recently Alvarez et al. 189 using red illumination reported similar results in the photoconductivity of undoped diamond. Ramesham et al. 54, 190 have studied undoped diamond films using ac impedance. They reported data for the double layer capacitance, solution resistance, film resistance, film capacitance and polarization resistance. Granger et al. 70 using undoped diamond have performed flow analysis and liquid chromatography of different organic compounds like azides, chlorpromazime, catecholamines and ascorbic acid.   

 

1.6. Possible lines of investigation

 

Despite the many efforts using boron doped polycrystalline diamond as an electrode semiconducting behaviour has not been reported for boron doped diamond.

 

Limited studies have been done to characterise the importance of the surface termination in the highly boron doped diamond electrochemistry. Being more specific there are almost no studies that describe the importance of the sub surface regions in the redox reactions of diamond electrodes.

 

Diamond as a heat sink has been described in commercial applications. Only Valdes et al. 191-193 have pointed out that diamond may be used as a heat sink in liquid media (aqueous solutions) for describing electrochemical systems using relaxation techniques.

 

1.7. Summary

 

Diamond shows exceptional properties that have been exploited since inexpensive synthesis methods were developed. Some diamond commercial applications are already on the market. Plenty of electrochemical experiments have been done using highly boron doped diamond in aqueous media. The number of studies in non aqueous media is very limited. The influence of the subsurface on the electrochemical properties is poorly characterised. Semiconducting behaviour of diamond electrodes has not been reported. Diamond used as a heat sink in liquid media has not been described fully.

 

1.8. Thesis outline

 

·        Chapter one: Introduction

 

-         This chapter outlines the properties of diamond and procedures for synthesis detailed.

-         Commercial applications of diamond are given.

-         Diamond electrochemistry literature is summarised and possible routes of investigation are given for the thesis.

-         A brief summary of the work presented in the thesis is outlined at the end of the chapter

 

·      Chapter two: Diamond growth and characterization

 

-         This chapter outlines the diamond growth methods and explains the method that was chosen for these studies.

-         The main components of the diamond growth apparatus are described

-         Scanning electron microscopy and Raman spectroscopy were utilised to describe and characterise the diamond films. Results are presented.

 

·       Chapter three: Electrical contacts to semiconducting diamond   

 

-         This chapter describes the electrical contact between the copper connecting wire and the diamond film.

-         Conditions to obtain an Ohmic contact are discussed.

-         Details of the fabrication and characterisation of indium-gallium contacts, silver paint contacts, gold contacts, three layer metal contacts and titanium underlayer contacts are given.

-         The suitable conditions for each electrical contact are discussed.

 

·       Chapter four: Electrochemical theory for diamond electrodes

 

-         This chapter outlines the standard electrochemical theory and a new theory is developed based on surface state mediated electron transfer.

-         A comparison is made between metal and semiconductor behaviour of the diamond electrodes deduced from the new theory.

 

·       Chapter five: Electrochemical studies of moderately boron doped diamond in non aqueous electrolyte

 

-         This chapter outlines the characterisation of moderately boron doped diamond films using acetonitrile as a solvent

-         Results of Mott-Schottky analysis and cyclic voltammetry of two standard redox couple are reported. Also the influence of the surface bond termination is analysed.

-         Semiconductor behaviour is shown for moderated boron doped diamond films

 

·       Chapter six: The influence of surface preparation on the electrochemisty of doped diamond

 

-         This chapter describes the influence of the surface bond termination using the reduction mechanism of benzoquinone.

-         Cyclic voltammetric behaviour of hydrogen and oxygen terminated diamond is shown.

-         Mechanism of benzoquinone for hydrogen terminated diamond is related with sub-surface diamond structure.

 

·          Chapter seven: Photocurrent measurements: a method to characterise surface states in CVD diamond

 

-         This chapter outlines the use of photocurrent experiments to characterise possible surface states.

 

·       Chapter eight: Temperature modulated open circuit potential spectroscopy

 

-         This chapter describes a new technique based on the temperature jump method for an electrochemical system at open circuit.

-         A new theory for the experiment is presented.

-         Experimental results are compared with the theory.

 

 

·       Chapter nine: Temperature modulated ac voltammetry

 

-         This chapter using a similar set up optimised to that described in chapter 8.

-         A new theory is presented

-         Experimental results are compared with the theoretical ones.

 

·             Chapter ten: Conclusions

 

1.9. References

 

1              C. E. Troupe, I. C. Drummond, C. Graham, J. Grice, P. John, J. I. B. Wilson, M. G. Jubber, and N. A. Morrison, Diam. Relat. Mater., 1998, 7, 575.

2              T. N. Rao, I. Yagi, T. Miwa, D. A. Tryk, and A. Fujishima, Anal. Chem., 1999, 71, 2506.

3              A. Denisenko, A. Aleksov, and E. Kohn, Diam. Relat. Chem., 2001, 10, 667.

4              N. Spataru, T. N. Rao, D. A. Tryk, and A. Fujishima, J. Electrochem. Soc., 2001, 148, E112.

5              N. Spataru, B. V. Sarada, E. Popa, D. A. Tryk, and A. Fujishima, Anal. Chem., 2001, 73, 514.

6              R. Uchikado, T. N. Rao, D. A. Tryk, and A. Fujishima, Chem. Lett., 2001, 144.

7              K. Ohnishi, Y. Einaga, H. Notsu, C. Terashima, T. N. Rao, S. G. Park, and A. Fujishima, Electrochem. Solid State Lett., 2002, 5, D1.

8              C. Prado, G. U. Flechsig, P. Grundler, J. S. Foord, F. Marken, and R. G. Compton, Analyst, 2002, 127, 329.

9              F. Marken, C. P. Paddon, and D. Asogan, Electrochem. Commun., 2002, 4, 62.

10             R. G. Compton, F. Marken, C. H. Goeting, R. A. J. McKeown, J. S. Foord, G. Scarsbrook, R. S. Sussman, and A. J. Whitehead, Chem. Commun., 1998, 1961.

11             C. H. Goeting, F. Marken, R. G. Compton and J. S. Foord, Chem. Commun., 1999, 17, 1697.

12             C. H. Goeting, J. S. Foord, F. Marken, and R. G. Compton, Diam. Relat. Chem., 1999, 8, 824.

13             A. J. Saterlay, S. J. Wilkins, C. H. Goeting, J. S. Foord, R. G. Compton, and F. Marken, J. Solid State Electrochem., 2000, 4, 383.

14             A. J. Saterlay, F. Marken, J. S. Foord, and R. G. Compton, Talanta, 2000, 53, 403.

15             J. S. Foord, K. B. Holt, R. G. Compton, F. Marken, and D. H. Kim, Diam. Relat. Chem., 2001, 10, 662.

16             K. B. Holt, J. Del Campo, J. S. Foord, R. G. Compton, and F. Marken, J. Electroanal. Chem., 2001, 513, 94.

17             A. J. Saterlay, S. J. Wilkins, K. B. Holt, J. S. Foord, R. G. Compton, and F. Marken, J. Electrochem. Soc., 2001, 148, E66.

18             J. D. Wadhawan, F. J. Del Campo, R. G. Compton, J. S. Foord, F. Marken, S. D. Bull, S. G. Davies, D. J. Walton, and S. Ryley, J. Electroanal. Chem., 2001, 507, 135.

19             E. Pace, A. Pini, G. Corti, F. Bogani, A. Vinattieri, C. S. J. Pickles, and R. Sussmann, Diam. Relat. Chem., 2001, 10, 736.

20             J. M. Stotter, S. Haymond, J. E. Butler, G. M. Swain, and J. K. Zak, Abstr. Pap. Am. Chem. Soc., 2001, 222, 117.

21             J. K. Zak, J. E. Butler, and G. M. Swain, Anal. Chem., 2001, 73, 908.

22             C. S. J. Pickles and T. D. Madgwick, Diam. Relat. Chem., 2000, 9, 916.

23             E. Bustarret, F. Pruvost, M. Bernard, C. Cytermann, and C. Uzan-Saguy, Phys. Status Solidi A-Appl. Res., 2001, 186, 303.

24             S. E. Coe and R. S. Sussmann, Diam. Relat. Chem., 2000, 9, 1726.

25             K. Hayashi, S. Yamanaka, H. Watanabe, T. Sekiguchi, H. Okushi, and K. Kajimura, J. Appl. Phys., 1997, 81, 744.

26             K. Hayashi, S. Yamanaka, H. Watanabe, T. Sekiguchi, H. Okushi, and K. Kajimura, J. Appl. Phys., 1998, 81, 744.

27             R. Locher, J. Wagner, F. Fuchs, M. Maier, P. Gonon, and P. Koidl, Diam. Relat. Chem., 1995, 4, 678.

28             G. Piantanida, A. Breskin, R. Chechik, O. Katz, A. Laikhtman, A. Hoffman, and C. Coluzza, J. Appl. Phys., 2001, 89, 8259.

29             H. Murakami, M. Yokoyama, S. M. Lee, and T. Ito, Appl. Surf. Sci., 2001, 175, 474.

30             J. S. Foord, L. C. Hian, and R. B. Jackman, Diam. Relat. Chem., 2001, 10, 710.

31             Y. M. Wang, K. W. Wong, S. T. Lee, M. Nishitani-Gamo, I. Sakaguchi, K. P. Loh, and T. Ando, Diam. Relat. Chem., 2000, 9, 1582.

32             J. Ristein, Diam. Relat. Chem., 2000, 9, 1129.

33             J. Ristein, F. Maier, M. Riedel, J. B. Cui, and L. Ley, Phys. Status Solidi A-Appl. Res., 2000, 181, 65.

34             N. Koenigsfeld, B. Philosoph, and R. Kalish, Diam. Relat. Chem., 2000, 9, 1218.

35             Y. D. Kim, W. Choi, H. Wakimoto, S. Usami, H. Tomokage, and T. Ando, Diam. Relat. Chem., 2000, 9, 1096.

36             J. B. Cui, J. Ristein, M. Stammler, K. Janischowsky, G. Kleber, and L. Ley, Diam. Relat. Chem., 2000, 9, 1143.

37             K. W. Wong, Y. M. Wang, S. T. Lee, and R. W. M. Kwok, Diam. Relat. Chem., 1999, 8, 1885.

38             L. Diederich, O. M. Kuttel, P. Aebi, and L. Schlapbach, Diam. Relat. Chem., 1999, 8, 743.

39             L. Diederich, P. Aebi, O. M. Kuttel, and L. Schlapbach, Surf. Sci., 1999, 424, L314.

40             J. B. Cui, R. Graupner, J. Ristein, and L. Ley, Diam. Relat. Chem., 1999, 8, 748.

41             M. J. Rutter and J. Robertson, Phys. Rev.B, 1998, 57, 9241.

42             J. Robertson and M. J. Rutter, Diam. Relat. Chem., 1998, 7, 620.

43             L. Diederich, O. Kuttel, P. Aebi, and L. Schlapbach, Surf. Sci., 1998, 418, 219.

44             J. B. Cui, J. Ristein, and L. Ley, Phys. Rev. Lett., 1998, 81, 429.

45             P. K. Baumann and R. J. Nemanich, J. Appl. Phys., 1998, 83, 2072.

46             T. P. Humphreys, R. E. Thomas, D. P. Malta, J. B. Posthill, M. J. Mantini, R. A. Rudder, G. C. Hudson, R. J. Markunas, and C. Pettenkofer, Appl. Phys. Lett., 1997, 70, 1257.

47             P. K. Baumann, S. P. Bozeman, B. L. Ward, and R. J. Nemanich, Diam. Relat. Chem., 1997, 6, 398.

48             J. Vanderweide, Z. Zhang, P. K. Baumann, M. G. Wensell, J. Bernholc, and R. J. Nemanich, Phys. Rev.B, 1994, 50, 5803.

49             J. Vanderweide and R. J. Nemanich, Phys. Rev.B, 1994, 49, 13629.

50             A. Y. Sakharova, Y. V. Pleskov, F. Diquarto, S. Piazza, C. Sunseri, I. G. Teremetskaya, and V. P. Varnin, J. Electrochem. Soc., 1995, 142, 2704.

51             J. Shirafuji and T. Sugino, Diam. Relat. Chem., 1996, 5, 706.

52             P. Gonon, S. Prawer, D. N. Jamieson, and K. W. Nugent, Diam. Relat. Chem., 1997, 6, 314.

53             K. Hayashi, H. Watanabe, S. Yamanaka, T. Sekiguchi, H. Okushi, and K. Kajimura, Diam. Relat. Chem., 1997, 6, 303.

54             R. Ramesham and M. F. Rose, Diam. Relat. Chem., 1997, 6, 17.

55             H. J. Looi, R. B. Jackman, and J. S. Foord, Appl. Phys. Lett., 1998, 72, 353.

56             P. W. May, S. Hohn, M. N. R. Ashfold, W. N. Wang, N. A. Fox, T. J. Davis, and J. W. Steeds, J. Appl. Phys., 1998, 84, 1618.

57             P. W. May, S. Hohn, W. N. Wang, and N. A. Fox, Appl. Phys. Lett., 1998, 72, 2182.

58             P. W. May, J. C. Stone, M. N. R. Ashfold, K. R. Hallam, W. N. Wang, and N. A. Fox, Diam. Relat. Chem., 1998, 7, 671.

59             E. Rohrer, C. E. Nebel, M. Stutzmann, A. Floter, R. Zachai, X. Jiang, and C. P. Klages, Diam. Relat. Chem., 1998, 7, 879.

60             F. Torrealba-Anzola, A. Chambaudet, J. G. Theobald, M. Jouffroy, C. Jany, F. Foulon, P. Bergonzo, A. Gicquel, and A. Tardieu, Diam. Relat. Chem., 1998, 7, 1338.

61             C. L. Wang, A. Hatta, N. Jiang, J. H. Won, T. Ito, A. Hiraki, Z. S. Jin, and G. T. Zou, Diam. Relat. Chem., 1998, 7, 748.

62             P. W. May, M. T. Kuo, and M. N. R. Ashfold, Diam. Relat. Chem., 1999, 8, 1490.

63             M. Benabdesselam, P. Iacconi, D. Briand, T. Lapraz, E. Gheeraert, and A. Deneuville, Diam. Relat. Chem., 2000, 9, 56.

64             B. R. Huang, C. H. Wu, and R. F. Sheu, Diam. Relat. Chem., 2000, 9, 73.

65             C. E. Nebel, A. Waltenspiel, M. Stutzmann, M. Paul, and L. Schafer, Diam. Relat. Chem., 2000, 9, 404.

66             L. Pereira, E. Pereira, and H. Gomes, Diam. Relat. Chem., 2000, 9, 1621.

67             Y. B. Xia, T. Sekiguchi, W. J. Zhang, X. Jiang, J. H. Ju, L. J. Wang, and T. Yao, Diam. Relat. Chem., 2000, 9, 1636.

68             B. J. Lee, B. T. Ahn, J. K. Lee, and Y. J. Baik, Diam. Relat. Chem., 2001, 10, 2147.

69             D. Tromson, P. Bergonzo, A. Brambilla, C. Mer, and F. Foulon, Diam. Relat. Chem., 2000, 9, 1091.

70             M. C. Granger, J. S. Xu, J. W. Strojek, and G. M. Swain, Anal. Chim. Acta, 1999, 397, 145.

71             R. F. Davis, Journal of Crystal Growth, 1994, 137, 161.

72             D. J. Twitchen, C. S. J. Pickles, S. E. Coe, R. S. Sussmann, and C. E. Hall, Diam. Relat. Chem., 2001, 10, 731.

73             A. Vlasov, V. Ralchenko, S. Gordeev, D. Zakharov, I. Vlasov, A. Karabutov, and P. Belobrov, Diam. Relat. Chem., 2000, 9, 1104.

74             H. P. Ho, K. C. Lo, S. C. Tjong, and S. T. Lee, Diam. Relat. Chem., 2000, 9, 1312.

75             S. Ertl, M. Adamschik, P. Schmid, P. Gluche, A. Floter, and E. Kohn, Diam. Relat. Chem., 2000, 9, 970.

76             J. L. Davidson, W. P. Kang, Y. Gurbuz, K. C. Holmes, L. G. Davis, A. Wisitsora-at, D. V. Kerns, R. L. Eidson, and T. Henderson, Diam. Relat. Chem., 1999, 8, 1741.

77             E. Worner, C. Wild, W. MullerSebert, R. Locher, and P. Koidl, Diam. Relat. Chem., 1996, 5, 688.

78             J. Lee, D. A. Tryk, A. Fujishima, and S. M. Park, Chem. Commun., 2002, 486.

79             F. J. Del Campo, C. H. Goeting, D. Morris, J. S. Foord, A. Neudeck, R. G. Compton, and F. Marken, Electrochem. Solid State Lett., 2000, 3, 224.

80             P. A. Michaud, E. Mahe, W. Haenni, A. Perret, and C. Comninellis, Electrochem. Solid State Lett., 2000, 3, 77.

81             R. Tenne and C. Levy-Clement, Israel J. Chem. , 1998, 38, 57.

82             F. Bouamrane, A. Tadjeddine, J. E. Butler, R. Tenne, and C. Levy-Clement, J. Electroanal. Chem., 1996, 405, 95.

83             C. Reuben, E. Galun, H. Cohen, R. Tenne, R. Kalish, Y. Muraki, K. Hashimoto, A. Fujishima, J. E. Butler, and C. Levy-Clement, J. Electroanal. Chem., 1995, 396, 233.

84             G. M. Swain, J. Electrochem. Soc., 1994, 141, 3382.

85             R. Tenne, K. Patel, K. Hashimoto, and A. Fujishima, J. Electroanal. Chem., 1993, 347, 409.

86             F. P. Bundy, J. Geophys. Res., 1980, 85, 6930.

87             E. Kohn, M. Adamschik, P. Schmid, S. Ertl, and A. Floter, Diam. Relat. Chem., 2001, 10, 1684.

88             A. Fujishima and T. N. Rao, Diam. Relat. Chem., 2001, 10, 1799.

89             A. Deneuville and E. Gheeraert, Vide-Sci. Techn. Appl., 2001, 56, 427.

90             K. L. Jackson, D. L. Thurston, P. J. Boudreaux, R. W. Armstrong, and C. C. M. Wu, J. Mater. Sci., 1997, 32, 5035.

91             P. J. Boudreaux, Applications of Diamond Films and Related Materials: 3rd International Conference, Washington, D. C., 1995, p. 603.

92             G. Lu, Applications of Diamond Films and Related Materials: 2nd International Conference, Tokio, 1993.

93             C. T. Troy, Photon. Spect., 1992, 26, 28.

94             Y. C. Yu, J. H. Huang, and I. N. Lin, J. Vac. Sci. Technol. B, 2001, 19, 975.

95             A. Wisitsora-at, W. P. Kang, J. L. Davidson, Y. Gurbuz, and D. V. Kerns, Diam. Relat. Chem., 1999, 8, 1220.

96             A. N. Obraztsov, I. Y. Pavlovsky, A. P. Volkov, E. V. Rakova, and S. P. Nagovitsyn, J. Electrochem. Soc., 1998, 145, 2572.

97             R. J. Nemanich, P. K. Baumann, M. C. Benjamin, O.-H. Nam, A. T. Sowers, B. L. Ward, H. A. de, and R.F.Davis, Appl. Surf. Sci., 1998, 130, 694.

98             M. W. Geis, N. N. Efremow, K. E. Krohn, J. C. Twichell, T. M. Lyszczarz, R. Kalish, J. A. Greer, and M.D.Tabat, Nature, 1998, 393, 431.

99             B. L. Druz, V. I. Polyakov, A. V. Karabutov, N. M. Rossukanyi, A. I. Rukovishnicov, E. Ostan, A. Hayes, V. D. Frolov, and V. I. Konov, Diam. Relat. Chem., 1998, 7, 695.

100           W. N. Wang, N. A. Fox, D. Richardson, G. M. Lynch, and J. W. Steeds, J. Appl. Phys., 1997, 81, 1505.

101           T. Sugino, Y. Iwasaki, S. Kawasaki, R. Hattori, and J. Shirafuji, Diam. Relat. Chem., 1997, 6, 889.

102           N. A. Fox, W. N. Wang, T. J. Davis, J. W. Steeds, and P. W. May, Appl. Phys. Lett., 1997, 71, 2337.

103           M. Mankos, R. M. Tromp, and M. C. R. a. E. Cartier, Phys. Rev. Lett, 1996, 76, 3200.

104           W. L. Wang, K. J. Liao, R. Q. Zhang, and C. Y. Kong, Mater. Sci. Eng. B-Solid State Mater. Adv. Technol., 2001, 85, 169.

105           C. Wild, 'Low pressure Synthetic Diamond: Manufacturing and Applications', ed. B.Dischler, 1998.

106           M. Chowalla, Diam. Relat. Chem., 2001, 10, 1011.

107           S. Ertl, P. Gluche, A. Floter, R. Rosch, and E. Kohn, International Diamond Meeting 2000, Porto, 2000.

108           H. Sein, W. Ahmed, and C. Rego, Diam. Relat. Mater., 2002, 11, 731.

109           Y. V. Pleskov, A. Y. Sakharova, M. D. Krotova, L. L. Bouilov, and B. P. Spitsyn, J. Electroanal. Chem., 1987, 228, 19.

110           C. Terashima, T. N. Rao, B. V. Sarada, D. A. Tryk, and A. Fujishima, Anal. Chem., 2002, 74, 895.

111           T. N. Rao, B. H. Loo, B. V. Sarada, C. Terashima, and A. Fujishima, Anal. Chem., 2002, 74, 1578.

112           C. Prado, S. J. Wilkins, F. Marken, and R. G. Compton, Electroanalysis, 2002, 14, 262.

113           A. Manivannan, M. S. Seehra, D. A. Tryk, and A. Fujishima, Anal. Lett., 2002, 35, 355.

114           M. Hyde, A. J. Saterlay, S. J. Wilkins, J. S. Foord, R. G. Compton, and F. Marken, J. Solid State Electrochem., 2002, 6, 183.

115           M. A. Witek and G. M. Swain, Anal. Chim. Acta, 2001, 440, 119.

116           M. A. Witek and G. M. Swain, Abstr. Pap. Am. Chem. Soc., 2001, 222, 59.

117           D. A. Tryk, K. Tsunozaki, T. N. Rao, and A. Fujishima, Diam. Relat. Chem., 2001, 10, 1804.

118           Y. C. Tsai, B. A. Coles, K. Holt, J. S. Foord, F. Marken, and R. G. Compton, Electroanalysis, 2001, 13, 831.

119           H. Notsu, T. Fukazawa, T. Tatsuma, D. A. Tryk, and A. Fujishima, Electrochem. Solid State Lett., 2001, 4, H1.

120           F. Marken, R. G. Compton, C. H. Goeting, J. S. Foord, S. D. Bull, and S. G. Davies, J. Solid State Electrochem., 2001, 5, 88.

121           F. Marken, Y. C. Tsai, A. J. Saterlay, B. A. Coles, D. Tibbetts, K. Holt, C. H. Goeting, J. S. Foord, and R. G. Compton, J. Solid State Electrochem., 2001, 5, 313.

122           M. C. Granger, M. Witek, J. S. Xu, J. Wang, M. Hupert, A. Hanks, M. D. Koppang, J. E. Butler, G. Lucazeau, M. Mermoux, J. W. Strojek, and G. M. Swain, Anal. Chem., 2000, 72, 3793.

123           O. Chailapakul, P. Aksharanandana, T. Frelink, Y. Einaga, and A. Fujishima, Sens. Actuator B-Chem., 2001, 80, 193.

124           B. V. Sarada, T. N. Rao, D. A. Tryk, and A. Fujishima, Anal. Chem., 2000, 72, 1632.

125           T. N. Rao, B. V. Sarada, D. A. Tryk, and A. Fujishima, J. Electroanal. Chem., 2000, 491, 175.

126           T. N. Rao and A. Fujishima, Diam. Relat. Chem., 2000, 9, 384.

127           H. Notsu, I. Yagi, T. Tatsuma, D. A. Tryk, and A. Fujishima, J. Electroanal. Chem., 2000, 492, 31.

128           C. H. Goeting, F. Marken, A. Gutierrez-Sosa, R. G. Compton, and J. S. Foord, Diam. Relat. Chem., 2000, 9, 390.

129           J. S. Xu and G. M. Swain, Anal. Chem., 1999, 71, 4603.

130           T. Kuo, R. L. McCreery, and G. M. Swain, Electrochem. Solid State Lett., 1999, 2, 288.

131           M. D. Koppang, M. Witek, J. Blau, and G. M. Swain, Anal. Chem., 1999, 71, 1188.

132           F. Beck, H. Krohn, W. Kaiser, M. Fryda, C. P. Klages, and L. Schafer, Electrochim. Acta, 1998, 44, 525.

133           C. H. Goeting, F. Jones, J. S. Foord, J. C. Eklund, F. Marken, R. G. Compton, P. R. Chalker, and C. Johnston, J. Electroanal. Chem., 1998, 442, 207.

134           R. Ramesham, Thin Solid Films, 1998, 315, 222.

135           Z. Y. Wu, T. Yano, D. A. Tryk, K. Hashimoto, and A. Fujishima, Chem. Lett., 1998, 503.

136           T. Yano, D. A. Tryk, K. Hashimoto, and A. Fujishima, J. Electrochem. Soc., 1998, 145, 1870.

137           R. DeClements and G. M. Swain, J. Electrochem. Soc., 1997, 144, 856.

138           L.-F. Li, S. Totir, B. Miller, G. Chottiner, A. Argoitia, J. C. Angus, and D. Scherson, J. Am. Chem. Soc., 1997, 119, 7875.

139           H. B. Martin, A. Argoitia, U. Landau, A. B. Anderson, and J. C. Angus, J. Electrochem. Soc., 1996, 143, L133.

140           Y. V. Pleskov, V. V. Elkin, M. A. Abaturov, M. D. Krotova, V. Y. Mishuk, V. P. Varnun, and I. G. Teremetskaya, J. Electroanal. Chem., 1996, 413, 105.

141           N. Vinokur, B. Miller, Y. Avyigal, and R. Kalish, J. Electrochem. Soc., 1996, 143, L238.

142           J. W. Strojek, M. C. Granger, G. M. Swain, T. Dallas, and M. W. Holtz, Anal. Chem., 1996, 68, 2031.

143           S. Alehashem, F. Chambers, J. W. Strojek, G. M. Swain, and R. Ramesham, Anal. Chem., 1995, 67, 2812.

144           G. Swain, Adv. Mater., 1994, 6, 388.

145           G. M. Swain and R. Ramesham, Anal. Chem., 1993, 65, 345.

146           J. C. Angus and C. C. Hayman, Science, 1988, 241, 913.

147           P. K. Bachmann and R. Messier, Chem. Eng. News, 1989, 67, 24.

148           M. W. Geis and J. C. Angus, Sci. Am., 1992, 267, 84.

149           M. W. Geis and J. C. Angus, Sci. Am., 1994, 270, 10.

150           R. Ramesham, D. C. Hill, S. R. Best, M. F. Rose, and R. F. Askew, Thin Solid Films, 1995, 257, 68.

151           A. J. Saterlay, J. S. Foord, and R. G. Compton, Electroanalysis, 2001, 13, 1065.

152           M. A. Rodrigo, P. A. Michaud, I. Duo, M. Panizza, G. Cerisola, and C. Comninellis, J. Electrochem. Soc., 2001, 148, D60.

153           M. Panizza, P. A. Michaud, G. Cerisola, and C. Comninellis, Electrochem. Commun., 2001, 3, 336.

154           M. Panizza, P. A. Michaud, G. Cerisola, and C. Comninellis, J. Electroanal. Chem., 2001, 507, 206.

155           J. Iniesta, P. A. Michaud, M. Panizza, and C. Comninellis, Electrochem. Commun., 2001, 3, 346.

156           J. Iniesta, P. A. Michaud, M. Panizza, G. Cerisola, A. Aldaz, and C. Comninellis, Electrochim. Acta, 2001, 46, 3573.

157           P. L. Hagans, P. M. Natishan, B. R. Stoner, and W. E. O'Grady, J. Electrochem. Soc., 2001, 148, E298.

158           L. Gherardini, P. A. Michaud, M. Panizza, C. Comninellis, and N. Vatistas, J. Electrochem. Soc., 2001, 148, D78.

159           D. Gandini, E. Mahe, P. A. Michaud, W. Haenni, A. Perret, and C. Comninellis, J. Appl. Electrochem., 2000, 30, 1345.

160           R. Ramesham, Thin Solid Films, 1999, 339, 82.

161           Y. V. Pleskov, J. Anal. Chem., 2000, 55, 1045.

162           I. Yagi, H. Notsu, T. Kondo, D. A. Tryk, and A. Fujishima, J. Electroanal. Chem., 1999, 473, 173.

163           E. Popa, H. Notsu, T. Miwa, D. A. Tryk, and A. Fujishima, Electrochem. Solid State Lett., 1999, 2, 49.

164           Y. V. Pleskov, Y. E. Evstefeeva, M. D. Krotova, and A. V. Laptev, Electrochim. Acta, 1999, 44, 3361.

165           S. Nakabayashi, D. A. Tryk, A. Fujishima, and N. Ohta, Chem. Phys. Lett., 1999, 300, 409.

166           A. Manivannan, D. A. Tryk, Fujishima, and A., Electrochem. Solid State Lett., 1999, 2, 455.

167           M. C. Granger and G. M. Swain, J. Electrochem. Soc., 1999, 146, 4551.

168           J. Xu, Q. Chen, and G. M. Swain, Anal.Chem., 1998, 70, 3146.

169           G. M. Swain, A. B. Anderson, and a. J. C. Angus, MRS Bulletin, 1998, 56.

170           A. D. Modestov, Y. E. Evstefeeva, Y. V. Pleskov, V. M. Mazin, V. P. Varnin, and I. G. Teremetskaya, J. Electroanal. Chem., 1997, 431, 211.

171           S. Jolley, M. Koppang, T. Jackson, and G. M. Swain, Anal. Chem., 1997, 69, 4099.

172           Q. Chen, M. C. Granger, T. E. Lister, and G. M. Swain, J. Electrochem. Soc., 1997, 144, 3806.

173           Y. Kittaka, M. Ito, S. Yoshihara, T. Shirakashi, K. Hashimoto, D. A. Tryk, and A. Fujishima, Electrochemistry, 2000, 68, 972.

174           T. Yano, E. Popa, D. A. Tryk, K. Hashimoto, and A. Fujishima, J. Electrochem. Soc., 1999, 146, 1081.

175           J. van de Lagemaat, D. Vanmaekelbergh, and J. J. Kelly, J. Electroanal. Chem., 1999, 475, 139.

176           M. N. Latto, D. J. Riley, and P. W. May, Diam. Relat. Chem., 2000, 9, 1181.

177           M. Cannaerts, M. Nesladek, Z. Remes, C. Van Haesendonck, and L. M. Stals, Phys. Status Solidi A-Appl. Res., 2000, 181, 77.

178           H. Kiyota, H. Okushi, T. Ando, M. Kamo, and Y. Sato, Diam. Relat. Chem., 1996, 5, 718.

179           H. Kawarada, Surf. Sci. Rep., 1996, 26, 205.

180           H. Kiyota and E. Matsushima, Appl. Phys. Lett., 1995, 67, 3596.

181           S. A. Grot, G. S. Gildenblat, C. W. Hatfield, C. R. Wronski, A. R. Badzian, T. Badzian, and R. Messier, IEEE Electron Device Lett., 1990, 11, 100.

182           Y. V. Pleskov, V. M. Mazin, Y. E. Evstefeeva, V. P. Varnin, I. G. Teremetskaya, and V. A. Laptev, Electrochem. Solid State Lett., 2000, 3, 141.

183           Y. V. Pleskov, V. P. Varnin, I. G. Teremetskaya, and A. V. Churikov, J. Electrochem. Soc., 1997, 144, 175.

184           T. N. Rao, D. A. Tryk, K. Hashimoto, and A. Fujishima, J. Electrochem. Soc., 1999, 146, 680.

185           P. E. Pehrsson, J. P. Long, M. Marchywka, and J. E. Butler, App. Phys. Lett., 1995, 67, 3414.

186           K. Okano, S. Koizumi, S. R. P. Silva, and G. A. J. Amaratunga, Nature, 1996, 381, 140.

187           A. Y. Sakharova, L. Nyikos, and Y. V. Pleskov, Electrochim. Acta, 1992, 37, 973.

188           Z. Zhang, M. Wensell, and J. Bernholc, Phys. Rev.B, 1995, 51, 5291.

189           J. Alvarez, J. P. Kleider, P. Bergonzo, C. Mer, D. Tromson, A. Deneuville, and P. Muret, Diam. Relat. Mater., 2002, 11, 635.

190           R. Ramesham and M. F. Rose, Thin Solid Films, 1997, 300, 144.

191           J. L. Valdes and B. Miller, J. Phys. Chem., 1989, 93, 7275.

192           J. L. Valdes and B. Miller, J. Phys. Chem., 1988, 92, 525.

193           J. L. Valdes and B. Miller, J. Phys. Chem., 1988, 92, 4483.



ª In the chapter 2 synthesis processes of diamond are explained in more detail