Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T08:10:48.376Z Has data issue: false hasContentIssue false

Magnetotransport properties of Co-C granular thin films depending on the carbon sputtering power

Published online by Cambridge University Press:  29 August 2012

J.G Kang*
Affiliation:
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
M. Mizuguchi
Affiliation:
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
K. Takanashi
Affiliation:
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
Get access

Abstract

CoxC1-x granular films were deposited on Si substrates by a co-sputtering method. A large negative MR of 30.3% was obtained at 2 K for the sample prepared with the sputtering power of 50 W (C) and 4 W (Co). We have studied structural properties of Co-C granular films by Raman spectroscopy. Two peaks (D and G modes) from carbon bonds were clearly observed, and the intensity ratio of two peaks changed with the sputtering power, suggesting that the graphitization was promoted with the sputtering power. It was also revealed that the transport mechanism changed from tunneling to Mott’s variable range hopping and MR decreased with the sputtering power.

Type
Articles
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Gittleman, J.I., Goldstein, Y., and Bozowski, S., Phys. Rev. B 5, 3609 (1995)10.1103/PhysRevB.5.3609Google Scholar
[2] Milner, A., Gerber, A., Groisman, B., Karpovsky, M., and Gladkikh, A., Phys. Rev. B 76, 475 (1996)Google Scholar
[3] Fujimori, H., Mitani, S., Ohnuma, S., Mat. Sci. Eng. B 31, 219 (1995)10.1016/0921-5107(94)08032-1Google Scholar
[4] Mitani, S., Fujimori, H., Takanashi, K., Yakushiji, K., Ha, J.G., Takahashi, S., Maekawa, S., Ohnuma, S., Kobayashi, N., Masumoto, T., Ohnuma, M., Hono, K., J. Magn. Magn. Mater 198, 179184 (1999)10.1016/S0304-8853(98)01041-5Google Scholar
[5] Yu, T. and Chen, P., IEEE Trans. Magn. 47, pp. 34673469 (2011)10.1109/TMAG.2011.2158302Google Scholar
[6] Boff, M. A. S., Geshev, J., and Schmidt, J. E., Flores, W. H., Antunes, A. B., Gusmao, M. A., and Teixeira, S. R., J.Appl.Phys. 91, 9909 (2002)10.1063/1.1479481Google Scholar
[7] Zhao, B. and Yan, X., Physica A 241, 367376 (1997)10.1016/S0378-4371(97)00109-XGoogle Scholar
[8] Leveneur, J., Kennedy, J., Williams, G. V. M., Metson, J., and Markwitz, A., Appl. Phys. Lett. 98, 053111 (2011)10.1063/1.3553274Google Scholar
[9] Quan, Z., Xu, X., Li, X., Feng, Q. and Gehring, G. A., J. Appl. Phys. 108, 103912 (2010)10.1063/1.3511752Google Scholar
[10] Sheng, P., Ni, G., Yin, J.F., Zhang, Y., Tang, Z.Y., Zhou, S.M. and Jin, Q.Y., Journal of Alloys and Compounds 477, 3235 (2009)10.1016/j.jallcom.2008.10.123Google Scholar
[11] Quan, Z., Liu, W., Li, X., Xu, X., Addison, K., Score, D.S. and Gehring, G.A., Materials Letter 65, 29822984 (2011)10.1016/j.matlet.2011.06.027Google Scholar
[12] Weinforth, H., Somsen, C., Rellinghaus, B., Carl, A., Wassermann, E. F., and Weller, D., IEEE Trans. Magn. 34, pp.11321134 (1998)10.1109/20.706413Google Scholar
[13] Nie, X., Jiang, J. C., Tung, L. D., Spinu, L., and Meletis, E. I., Thin Solid Films 415, pp. 211218 (2002)10.1016/S0040-6090(02)00541-2Google Scholar
[14] Sugai, I., Sakai, S., Matsumoto, Y., Naramoto, H., Mitani, S., Takanashi, K. and Maeda, Y., J. Appl. Phys. 108, 063920 (2010)10.1063/1.3471800Google Scholar
[15] Sakai, S., Yakushiji, K., Mitani, S., Takanashi, K., Naramoto, H., Avramov, P. V., Narumi, K., Lavrentiev, V., and Maeda, Y., Appl. Phys. Lett. 89, 113118 (2006)10.1063/1.2354035Google Scholar
[16] Tang, R., Mizuguchi, M., Wang, H., Yu, R., and Takanashi, K., IEEE Trans. Magn. 46, 2144 (2010)10.1109/TMAG.2010.2043340Google Scholar
[17] Tai, F. C., Lee, S. C., Chen, J., Weid, C. and Change, S. H., J. Raman Spectrosc. 40, 10551059 (2009)10.1002/jrs.2234Google Scholar
[18] Ferrari, A. C. and Robertson, J., Phys. Rev. B. 61, 14095 (2000)10.1103/PhysRevB.61.14095Google Scholar
[19] Khun, N.W., Liu, E., Surf. Coat. Technol. 205, 853860 (2010)10.1016/j.surfcoat.2010.08.023Google Scholar
[20] Abeles, B., Sheng, P., Coutts, M. D., and Arie, Y., Adv. Phys. 24, 407461 (1975)10.1080/00018737500101431Google Scholar
[21] Mott, N.F., J.Non-Cryst.Solid 1 (1968)10.1016/0022-3093(68)90002-1Google Scholar