Abstract
Co-Al-O film was fabricated using the reactive r.f. magnetron sputtering technique. A maximum magnetoresistance (MR) of approximately 7% was established through optimizing the sputter deposition conditions such as sputter power and gas flow rate. TEM characterization of the film revealed a nano-granular structure that consisted of ferromagnetic grains with grain diameters on the order of several nm together with non-magnetic grain boundary layers with the thickness on the order of less than 1 nm. The large MR was attributed to electron tunneling thorough this very thin grain boundary layer between individual ferromagnetic grains.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
A. E. Berkowitz, M. J. Carely, J. R. Michell, A. P. Young, S. Zhang, F. E. Spada, F. T. Parker, A. Hutten and G. Thomas, Phys. Rev. Lett. 68 (1992) 3745.
J. Q. Xiao, J. S. Jiang and C. L. Chien, ibid. 68 (1992) 3749.
K. Takanashi, T. Sugawara, K. Hono and H. Fujimori, J. Appl. Phys. 76 (1994) 6790.
K. Takanashi, J. Park, T. Sugawara, K. Hono, A. Goto, H. Yasuoka and H. Fijimori, Thin Solid Films 275 (1996) 106.
T. Miyazaki and N. Tezuka, J. Magn. Magn. Mater. 151 (1995) 403.
H. Fujimori, S. Mitani and S. Ohnuma, Mater, Sci. Eng. B 31 (1995) 219.
H. Fujimori, S. Mitani and S. Ohnuma, J. Magn. Magn. Mater. 156 (1996) 311.
S. Mitani, H. Fujimori and S. Ohnuma, ibid. 165 (1997) 141.
S. Ohnuma, H. Fujimori, S. Mitani and T. Masumoto, J. Appl. Phys. 79 (1996) 5130.
M. Ohnuma, K. Hono, E. Abe, H. Onodera, S. Mitani and H. Fujimori, ibid. 82 (1997) 5646.
S. Foner, Rev. Sci. Instrum. 30 (1959) 548.
S. Foner and E. J. Mcniff, Jr, Rev. Sci. Instrum. 39 (1968) 171.
M. Julliere, Phys. Lett. 54A (1975) 225.
P. M. Tedrow and R. Meservey, Phys. Rev. Lett. 26 (1971) 192.
C. P. Bean, J. Appl. Phys. 26 (1955) 1381.
J. A. Thornton, J. Vac. Sci. Technol. 11 (1974) 666.
T. Sawasaki, K. Moriguchi, A. Yamasaki and S. Tanoue, J. Magn. Soc. Jpn. 23 (1999) 1293.
J. C. Slonczewski, Phys. Rev. B 39 (1989) 6995.
J. Mathon, ibid. 56 (1997) 11810.
S. Maekawa and J. Inoue, J. Magn. Magn. Mater. 156 (1996) 315.
M. Yonemura, S. Naga and K. Kamei, Jpn. J. Appl. Phys. 40 (2001) 740.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kamei, K., Yonemura, M. & Hanafusa, K. TEM characterization of Co-Al-O nano-granular TMR film. Journal of Materials Science: Materials in Electronics 12, 569–574 (2001). https://doi.org/10.1023/A:1012489503146
Issue Date:
DOI: https://doi.org/10.1023/A:1012489503146