Electrically conducting polymers: Science and technology

MRS Bulletin

Volumn 22, Issue 6, 1997, Pages 16-23

  Epstein, Arthur J ^a  

^a NONE

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EID: 0344716241     PISSN: 08837694     EISSN: None     Source Type: Journal    
DOI: 10.1557/S0883769400033583     Document Type: Article

References (102)

1. C.K. Chiang, C.R. Fincher, Jr., Y.W. Park, A.J. Heeger, H. Shirakawa, E.J. Louis, S.C. Gau, and A.G. MacDiarmid, Phys. Rev. Lett. 39 (1977) p. 1098.
2. R.S. Kohlman, J. Joo, and A.J. Epstein, in Physical Properties of Polymers Handbook, edited by J.E. Mark (AIP Press, Woodbury, NY, 1996) p. 453.
3. Proc. Int. Conf. on Science and Technology of Synthetic Metals, edited by Y.W. Park and H. Lee (Seoul, Korea, July 24-29, 1994) (Synth. Met. 69-71,1995); ibid., edited by Z.V. Vardeny and A.J. Epstein (Snowbird, Utah, July 28-August 2, 1996) (Synth. Met. 84-86 1997).
4. Proc. Int. Conf. on Science and Technology of Synthetic Metals, edited by Y.W. Park and H. Lee (Seoul, Korea, July 24-29, 1994) (Synth. Met. 69-71,1995); ibid., edited by Z.V. Vardeny and A.J. Epstein (Snowbird, Utah, July 28-August 2, 1996) (Synth. Met. 84-86 1997).
5. Proc. Int. Conf. on Science and Technology of Synthetic Metals, edited by Y.W. Park and H. Lee (Seoul, Korea, July 24-29, 1994) (Synth. Met. 69-71,1995); ibid., edited by Z.V. Vardeny and A.J. Epstein (Snowbird, Utah, July 28-August 2, 1996) (Synth. Met. 84-86 1997).
6. Proc. Int. Conf. on Science and Technology of Synthetic Metals, edited by Y.W. Park and H. Lee (Seoul, Korea, July 24-29, 1994) (Synth. Met. 69-71,1995); ibid., edited by Z.V. Vardeny and A.J. Epstein (Snowbird, Utah, July 28-August 2, 1996) (Synth. Met. 84-86 1997).
7. R. Kohlman and A.J. Epstein, in Handbook of Conducting Polymers, edited by T. Skothern, R.L. Elsenbaumer, and J. Reynolds (Marcel Dekker, Inc., New York) in press.
8. D. Baeriswyl, D.K. Campbell, and S. Mazumdar, in Conjugated Conducting Polymers, edited by H.G. Keiss (Springer-Verlag, Berlin, 1992) p. 7.
9. E.M. Conwell, JEEE Trans. Electr. Insulation EI-22 (1987) p. 591.
10. A.J. Heeger, S.A. Kivelson, J.R. Schrieffer, and W.P. Su, Rev. Mod. Phys. 60 (1988) p. 781.
11. J.M. Ginder and A.J. Epstein, Phys. Rev. B 41 (1990) p. 10674.
12. J. Libert, J.L. Brédas, and A.J. Epstein, Phys. Rev. B 51 (1995) p. 5711.
13. E. Jeckelmann and D. Baeriswyl, Synth. Met. 65 (1994) p. 211; S.N. Dixit and S. Mazumdar, Phys. Rev. B 29 (1984) p. 1824; W.K. Wu and S. Kivelson, ibid. 33 (1986) p. 8546; C. Wu, X. Sun, and K. Nasu, Phys. Rev. Lett. 59 (1987) p. 831.
14. E. Jeckelmann and D. Baeriswyl, Synth. Met. 65 (1994) p. 211; S.N. Dixit and S. Mazumdar, Phys. Rev. B 29 (1984) p. 1824; W.K. Wu and S. Kivelson, ibid. 33 (1986) p. 8546; C. Wu, X. Sun, and K. Nasu, Phys. Rev. Lett. 59 (1987) p. 831.
15. E. Jeckelmann and D. Baeriswyl, Synth. Met. 65 (1994) p. 211; S.N. Dixit and S. Mazumdar, Phys. Rev. B 29 (1984) p. 1824; W.K. Wu and S. Kivelson, ibid. 33 (1986) p. 8546; C. Wu, X. Sun, and K. Nasu, Phys. Rev. Lett. 59 (1987) p. 831.
16. E. Jeckelmann and D. Baeriswyl, Synth. Met. 65 (1994) p. 211; S.N. Dixit and S. Mazumdar, Phys. Rev. B 29 (1984) p. 1824; W.K. Wu and S. Kivelson, ibid. 33 (1986) p. 8546; C. Wu, X. Sun, and K. Nasu, Phys. Rev. Lett. 59 (1987) p. 831.
17. H.W. Gibson, F.C. Bailey, A.J. Epstein, H. Rommelmann, S. Kaplan, J. Harbour, X-Q. Yang, D.B. Tanner, and J.M. Pochan, J. Am. Chem. Soc. 105 (1983) p. 4417.
18. M.C. dos Santos and J.L. Brédas, Phys. Rev. Lett. 62 (1989) p. 2499; J.M. Ginder and A.J. Epstein, ibid. 64 (1990) p. 1184.
19. M.C. dos Santos and J.L. Brédas, Phys. Rev. Lett. 62 (1989) p. 2499; J.M. Ginder and A.J. Epstein, ibid. 64 (1990) p. 1184.
20. J.P. Pouget, Z. Oblakowski, Y. Nogami, P.A. Albouy, M. Laridjani, E.J. Oh, Y. Min, A.G. MacDiarmid, J. Tsukamoto, T. Ishiguro, and A.J. Epstein, Synth. Met. 65 (1994) p. 131.
21. N.S. Murthy, G.G. Miller, and R.H. Baughman, J. Chem. Phys. 89 (1988) p. 2523.
22. W.P. Su, J.R. Schrieffer, and A.J. Heeger, Phys. Rev. Lett. 42 (1979) p. 1698.
23. S.A. Brazovskii, Sov. Phys. JETP 28 (1978) p. 606.
24. M.J. Rice, Phys. Lett. 71A (1979) p. 152.
25. D.K. Campbell and A.R. Bishop, Phys. Rev. B 24 (1981) p. 4859.
26. S. Kivelson and W.K. Wu, ibid. 34 (1986) p. 5423.
27. X. Wei, B.C. Hess, Z.V. Vardeny, and F. Wudl, Phys. Rev, Lett. 68 (1992) p. 666; K.A. Coplin, S. Jasty, S.M. Long, S.K. Manohar, Y. Min, A.G. MacDiarmid, and A.J. Epstein, ibid. 72 (1994) p. 3206.
28. X. Wei, B.C. Hess, Z.V. Vardeny, and F. Wudl, Phys. Rev, Lett. 68 (1992) p. 666; K.A. Coplin, S. Jasty, S.M. Long, S.K. Manohar, Y. Min, A.G. MacDiarmid, and A.J. Epstein, ibid. 72 (1994) p. 3206.
29. H.A. Mizes and E.M. Conwell, Phys. Rev. B 50 (1994) p. 11243.
30. N.F. Colaneri, D.D.C. Bradley, R.H. Friend, P.L. Burn, A.B. Holmes, and C.W. Spangler, ibid. 42 (1990) p. 11670.
31. M. Yan, L.J. Rothberg, F. Papadimitrakopoulos, M.E. Galvin, and T.M. Miller, Phys. Rev. Lett. 72 (1994) p. 156; J.W. Blarchford, S.W. Jessen, L.B. Lin, J.J. Lih, T.L. Gustafson, A.J. Epstein, D.K. Fu, M.J. Marsella, T.M. Swager, A.G. MacDiarmid, S. Yamaguchi, and H. Hamaguchi, ibid. 76 p. 1513.
32. M. Yan, L.J. Rothberg, F. Papadimitrakopoulos, M.E. Galvin, and T.M. Miller, Phys. Rev. Lett. 72 (1994) p. 156; J.W. Blarchford, S.W. Jessen, L.B. Lin, J.J. Lih, T.L. Gustafson, A.J. Epstein, D.K. Fu, M.J. Marsella, T.M. Swager, A.G. MacDiarmid, S. Yamaguchi, and H. Hamaguchi, ibid. 76 p. 1513.
33. E.M. Conwell, H.A. Mizes, and S. Jeyadev, Phys. Rev. B 40 (1989) p. 1630.
34. S. Stafström, ibid. 43 (1991) p. 12437.
35. A.J. Epstein, J.M. Ginder, F. Zuo, R.W. Bigelow, H-S. Woo, D.B. Tanner, A.F. Richter, W-S. Huang, and A.C. MacDiarmid, Synth. Met. 18 (1987) p. 303.
36. S. Stafström, J.L. Brédas, A.J. Epstein, H-S. Woo, D.B. Tanner, W-S. Huang, and A.G. MacDiarmid, Phys. Rev. Lett. 59 (1987) p. 1474.
37. J.L. Brédas, B. Thémans, J.G. Fripiat, J.M. André, and R.R. Chance, Phys. Rev. B 29 (1984) p. 6761.
38. F. Genoud, M. Guglielmi, M. Nechtschein, E. Genies, and M. Salmon, Phys. Rev. Lett. 55 (1985) p. 118.
39. A.G. MacDiarmid and A.J. Epstein, Synth. Met. 65 (1994) p. 103.
40. Y. Cao and A.J. Heeger, ibid. 52 (1992) p. 193.
41. J. Yue and A.J. Epstein, J. Am. Chem. Soc. 112 (1990) p. 2800; X-L. Wei, Y.Z. Wang, S.M. Long, C. Bobecko, and A.J. Epstein, ibid. 118 (1996) p. 2545. W. Lee, G. Du, S.M. Long, S. Shimizu, T. Saitoh, M. Uzawa, and A.J. Epstein, Synth. Met. in press.
42. J. Yue and A.J. Epstein, J. Am. Chem. Soc. 112 (1990) p. 2800; X-L. Wei, Y.Z. Wang, S.M. Long, C. Bobecko, and A.J. Epstein, ibid. 118 (1996) p. 2545. W. Lee, G. Du, S.M. Long, S. Shimizu, T. Saitoh, M. Uzawa, and A.J. Epstein, Synth. Met. in press.
43. J. Yue and A.J. Epstein, J. Am. Chem. Soc. 112 (1990) p. 2800; X-L. Wei, Y.Z. Wang, S.M. Long, C. Bobecko, and A.J. Epstein, ibid. 118 (1996) p. 2545. W. Lee, G. Du, S.M. Long, S. Shimizu, T. Saitoh, M. Uzawa, and A.J. Epstein, Synth. Met. in press.
44. M. Bartonek and H. Kuzmany, ibid. 41-43 (1991) p. 607; K. Mizoguchi, T. Obana, S. Ueno, and K. Kume, ibid. 55-57 (1993) p. 601; F. Genoud, M. Nechtschein, and C. Santier, ibid. p. 642.
45. M. Bartonek and H. Kuzmany, ibid. 41-43 (1991) p. 607; K. Mizoguchi, T. Obana, S. Ueno, and K. Kume, ibid. 55-57 (1993) p. 601; F. Genoud, M. Nechtschein, and C. Santier, ibid. p. 642.
46. M. Bartonek and H. Kuzmany, ibid. 41-43 (1991) p. 607; K. Mizoguchi, T. Obana, S. Ueno, and K. Kume, ibid. 55-57 (1993) p. 601; F. Genoud, M. Nechtschein, and C. Santier, ibid. p. 642.
47. M.E. Jozefowicz, R. Laversanne, H.H.S. Javadi, A.J. Epstein, J.P. Pouget, X. Tang, and A.C. MacDiarmid, Phys. Rev. B 39 (1989) p. 12958.
48. J. Tsukamoto, Adv. Phys. 41 (1992) p. 509.
49. H. Naarmann and N. Theophilou, Synth. Met. 22 (1987) p. 1.
50. H. Shirakawa, Y-X. Zhang, T. Okuda, K. Sakamaki, and K. Akagi, ibid. 65 (1994).
51. (a) J. Tsukamoto, Adv. in Phys. 41 (1992) p. 509;
52. (b) H. Naarmann and N. Theophilou, Synth. Met. 22 (1987) p. 1;
53. (c) H. Shirakawa, Y.X. Zhang, T. Okuda, K. Sakamaki, and K. Akagi, Synth. Met. 65 (1994) p. 93;
54. (d) J-C. Chiang and A.G. MacDiarmid, Synth. Met. 13 (1986) p. 193;
55. (e) A.J. Epstein, H. Rommelmann, R. Bigelow, H.W. Gibson, D.M. Hoffman, and D.B. Tanner, Phys. Rev. Lett. 50 (1983) p. 1866;
56. (f) P. N. Adams, P. Laughlin, A.P. Monkman, and N. Bernhoeft, Solid State Commun. 91 (1994) p. 895; the value of conductivity reported in Figure 4 is for samples kindly provided by Dr. Monkman and co-workers, and measured at The Ohio State University;
57. (g) Y. Cao, P. Smith, and A.J. Heeger, Synth. Met. 48 (1992) p. 91;
58. (h) J. Joo, Z. Oblakowski, G. Du, J.P. Pouget, E.J. Oh, J.M. Weisinger, Y. Min, A.G. MacDiarmid, and A.J. Epstein, Phys. Rev. B 49 (1994) p. 2977;
59. (i) Y.Z. Wang, J. Joo, C-H. Hsu, J.P. Pouget, and A.J. Epstein, ibid. 50 (1994) p. 16811;
60. (j) Z.H. Wang, H.H.S. Javadi, A. Ray, A.G. MacDiarmid, and A.J. Epstein, ibid. 42 (1990) p. 5411;
61. (k) J. Yue, Z.H. Wang, K.R. Cromack, A.J. Epstein, and A.G. MacDiarmid, J. Am. Chem. Soc. 113 (1991) p. 2655;
62. (l) M. Yamaura, T. Hagiwara, and K. Iwata, Synth. Met. 26 (1988) p. 209;
63. (m,n) R.S. Kohlman, J. Joo, Y.Z. Wang, J.P. Pouget, H. Kaneko, T. Ishiguro, and A.J. Epstein, Phys. Rev. Lett. 74 (1995) p. 773; K. Sato, M. Yamaura, T. Hagiwara, K. Murata, and M. Tokumoto, Synth. Met. 40 (1991) p. 35;
64. (m,n) R.S. Kohlman, J. Joo, Y.Z. Wang, J.P. Pouget, H. Kaneko, T. Ishiguro, and A.J. Epstein, Phys. Rev. Lett. 74 (1995) p. 773; K. Sato, M. Yamaura, T. Hagiwara, K. Murata, and M. Tokumoto, Synth. Met. 40 (1991) p. 35;
65. (o) R.D. McCullough, S.P. Williams, S. Tristran-Nagle, M. Jayaraman, P.C. Ewbank, and L. Miller, ibid. 69 (1995) p. 279;
66. (p) J-E. Österholm, P. Passiniemi, H. Isotalo, and H. Stubb, ibid. 18 (1987) p. 213;
67. (q) T. Ohnishi, T. Noguchi, T. Nakano, M. Hirooka, and I. Murase, ibid. 41-43 (1991) p. 309;
68. (r) L.W. Shacklette, R.R. Chance, D.M. Ivory, G.G. Miller, and R.H. Baughman, ibid. 1 (1979) p. 307;
69. (s) G. Du, V.N. Prigodin, A. Burns, C.S. Wang, and A.J. Epstein (unpublished manuscript);
70. (t) A.J. Epstein, H. Rommelmann, M. Abkowitz, and H.W. Gibson, Phys. Rev. Lett. 47 (1981) p. 1549;
71. (u) A.J. Epstein, H. Rommelmann, and H.W. Gibson, Phys. Rev. B 31 (1985) p. 2502;
72. (v) F. Zuo, M. Angelopoulos, A.G. MacDiarmid, and A.J. Epstein, ibid. 39 (1989) p. 3570;
73. (w) J.C. Scott, P. Pfluger, M.T. Krounbi, and G.B. Street, ibid. 28 (1983) p. 2140;
74. (x) J-E. Österholm, P.P. Passiniemi, H. Isotalo, and H. Strubb, Synth. Met. 18 (1987) p. 213;
75. (y) G.E. Wnek, J.C. Chien, F.E. Karasz, and C.P. Lillya, Polymer 20 (1979) p. 1441;
76. (z) L.W. Shacklette, R.R. Chance, D.M. Ivory, G.G. Miller, and R.H. Baughman, Synth. Met. 1 (1979) p. 307.
77. C. Kittel, in Introduction to Solid State Physics (John Wiley & Sons, New York, 1986) p. 157.
78. P.W. Anderson, Phys. Rev. 109 (1958) p, 1492.
79. N.F. Mott and E. Davis, Electronic Processes in Non-Crystalline Materials (Clarendon Press, Oxford, 1979).
80. J.W. Blatchford and A.J. Epstein, Am. J. Phys. 64 (1996) p. 120.
81. Z.H. Wang, A. Ray, A.G. MacDiarmid, and A.J. Epstein, Phys. Rev. B 43 (1991) p. 4373; J. Joo, V.N. Prigodin, Y.G. Min, A.G. Mac-Diarmid, and A.J. Epstein, ibid. 50 (1994) p. 12226.
82. Z.H. Wang, A. Ray, A.G. MacDiarmid, and A.J. Epstein, Phys. Rev. B 43 (1991) p. 4373; J. Joo, V.N. Prigodin, Y.G. Min, A.G. Mac-Diarmid, and A.J. Epstein, ibid. 50 (1994) p. 12226.
83. R.S. Kohlman, J. Joo, Y.Z. Wang, J.P. Pouget, H. Kaneko, T. Ishiguro, and A.J. Epstein, Phys. Rev. Lett. 74 (1995) p. 773; R.S. Kohlman, J. Joo, Y.G. Min, A.G. MacDiarmid, and A.J. Epstein, ibid. 77 (1996) p. 2766.
84. R.S. Kohlman, J. Joo, Y.Z. Wang, J.P. Pouget, H. Kaneko, T. Ishiguro, and A.J. Epstein, Phys. Rev. Lett. 74 (1995) p. 773; R.S. Kohlman, J. Joo, Y.G. Min, A.G. MacDiarmid, and A.J. Epstein, ibid. 77 (1996) p. 2766.
85. T. Ishiguro, H. Kaneko, Y. Nogami, H. Nishiyama, J. Tsukamoto, A. Takahashi, M. Yamaura, and J. Sato, Phys. Rev. Lett. 69 (1992) p. 660; H. Kaneko, T. Ishiguro, J. Tsukamoto, and A. Takahashi, Solid State Commun. 90 (1994) p. 83.
86. T. Ishiguro, H. Kaneko, Y. Nogami, H. Nishiyama, J. Tsukamoto, A. Takahashi, M. Yamaura, and J. Sato, Phys. Rev. Lett. 69 (1992) p. 660; H. Kaneko, T. Ishiguro, J. Tsukamoto, and A. Takahashi, Solid State Commun. 90 (1994) p. 83.
87. J. Tanaka, C. Tanaka, T. Miyamae, M. Shimizu, S. Hasegawa, K. Kamiya, and K. Seki, Synth. Met. 65 (1994) p. 173.
88. N.F. Colaneri and L.W. Shacklette, IEEE Trans. Instrum. Meas. IM-41 (1992) p. 291; T. Taka, Synth. Met. 41-43 (1991) p. 1177;
89. N.F. Colaneri and L.W. Shacklette, IEEE Trans. Instrum. Meas. IM-41 (1992) p. 291; T. Taka, Synth. Met. 41-43 (1991) p. 1177;
90. J. Joo and A.J. Epstein, Appl. Phys. Lett. 65 (1994) p. 2278.
91. A.J. Epstein, J. Joo, C-Y. Wu, A. Benatar, C.F. Faisst, Jr., J. Zegarski, and A.G. MacDiarmid, in Intrinsically Conducting Polymers: An Emerging Technology, edited by M. Aldissi (Kluwer Academic Publishers, Netherlands, 1993) p. 165.
92. D.W. DeBerry, J. Electrochem. Soc. 132 (1985) p. 1022; N. Ahmad and A.G. MacDiarmid, Synth. Met. 78 (1996) p. 103; B. Wessling, Adv. Mater. 6 (1994) p. 226; W-K. Lu, R.L. Elsenbaumer, and B. Wessling, Synth. Met. 71 (1995) p. 2163; D.A. Wrobleski, B.C. Benicewicz, K,G. Thompson, and C.J. Bryan, ACS Polymer Preprints 35 (1994) p. 265; Y. Wei, J. Wang, X. Jia, J-M. Yeh, and P. Spellane, Polym. Mater. Sci. Eng. 72 (1995) p. 563.
93. D.W. DeBerry, J. Electrochem. Soc. 132 (1985) p. 1022; N. Ahmad and A.G. MacDiarmid, Synth. Met. 78 (1996) p. 103; B. Wessling, Adv. Mater. 6 (1994) p. 226; W-K. Lu, R.L. Elsenbaumer, and B. Wessling, Synth. Met. 71 (1995) p. 2163; D.A. Wrobleski, B.C. Benicewicz, K,G. Thompson, and C.J. Bryan, ACS Polymer Preprints 35 (1994) p. 265; Y. Wei, J. Wang, X. Jia, J-M. Yeh, and P. Spellane, Polym. Mater. Sci. Eng. 72 (1995) p. 563.
94. D.W. DeBerry, J. Electrochem. Soc. 132 (1985) p. 1022; N. Ahmad and A.G. MacDiarmid, Synth. Met. 78 (1996) p. 103; B. Wessling, Adv. Mater. 6 (1994) p. 226; W-K. Lu, R.L. Elsenbaumer, and B. Wessling, Synth. Met. 71 (1995) p. 2163; D.A. Wrobleski, B.C. Benicewicz, K,G. Thompson, and C.J. Bryan, ACS Polymer Preprints 35 (1994) p. 265; Y. Wei, J. Wang, X. Jia, J-M. Yeh, and P. Spellane, Polym. Mater. Sci. Eng. 72 (1995) p. 563.
95. D.W. DeBerry, J. Electrochem. Soc. 132 (1985) p. 1022; N. Ahmad and A.G. MacDiarmid, Synth. Met. 78 (1996) p. 103; B. Wessling, Adv. Mater. 6 (1994) p. 226; W-K. Lu, R.L. Elsenbaumer, and B. Wessling, Synth. Met. 71 (1995) p. 2163; D.A. Wrobleski, B.C. Benicewicz, K,G. Thompson, and C.J. Bryan, ACS Polymer Preprints 35 (1994) p. 265; Y. Wei, J. Wang, X. Jia, J-M. Yeh, and P. Spellane, Polym. Mater. Sci. Eng. 72 (1995) p. 563.
96. D.W. DeBerry, J. Electrochem. Soc. 132 (1985) p. 1022; N. Ahmad and A.G. MacDiarmid, Synth. Met. 78 (1996) p. 103; B. Wessling, Adv. Mater. 6 (1994) p. 226; W-K. Lu, R.L. Elsenbaumer, and B. Wessling, Synth. Met. 71 (1995) p. 2163; D.A. Wrobleski, B.C. Benicewicz, K,G. Thompson, and C.J. Bryan, ACS Polymer Preprints 35 (1994) p. 265; Y. Wei, J. Wang, X. Jia, J-M. Yeh, and P. Spellane, Polym. Mater. Sci. Eng. 72 (1995) p. 563.
97. D.W. DeBerry, J. Electrochem. Soc. 132 (1985) p. 1022; N. Ahmad and A.G. MacDiarmid, Synth. Met. 78 (1996) p. 103; B. Wessling, Adv. Mater. 6 (1994) p. 226; W-K. Lu, R.L. Elsenbaumer, and B. Wessling, Synth. Met. 71 (1995) p. 2163; D.A. Wrobleski, B.C. Benicewicz, K,G. Thompson, and C.J. Bryan, ACS Polymer Preprints 35 (1994) p. 265; Y. Wei, J. Wang, X. Jia, J-M. Yeh, and P. Spellane, Polym. Mater. Sci. Eng. 72 (1995) p. 563.
98. S. Jasty and A.J. Epstein, ibid. p. 565; M. Fahlman, S. Jasty, and A.J. Epstein, Synth. Met. in press.
99. S. Jasty and A.J. Epstein, ibid. p. 565; M. Fahlman, S. Jasty, and A.J. Epstein, Synth. Met. in press.
100. S. Karg, J.C. Scott, J.R. Salem, and M. Angelopoulos, ibid.
101. Y. Yang, E. Westerweele, C. Zhang, P. Smith, and A.J. Heeger, J. Appl. Phys. 77 (1995) p. 694.
102. Y.Z. Wang, D.D. Gebler, L.B. Lin, J.W. Blatchford, S.W. Jessen, H.L. Wang, and A.J. Epstein, Appl. Phys. Lett. 68 (1996) p. 894.