| Title |
Electronic Magnetic & Optical Materials ; Effect of Post-Annealing on Microstructure and Magnetoresistance of Sputtered Semimetal Bi Thin Film |
| Authors |
전민홍(M. H. Jeun); 장준연(J. Y. Chang); 한석희(S. H. Han); 한준현(J. H. Han); 이우영(W. Y. Lee) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Bismuth; Sputter; Semimetal; Magnetoresistance; MR; Spintronics |
| Abstract |
We explore the possibility of sputtered Bi thin film applicable for the spin device by investigating the change in microstructure and magneto-resistance (MR) of post-annealed Bi film. Randomly oriented fine grains of which size was measured to about 100 nm (nano meter) were found in as-sputtered Bi. Careful annealing done at only 1.4℃ below the melting temperature of Bi results in not only grain growth up to 1.2 pm but also textured grains well aligned to [003] preferred orientation of Bi. The MR for as-sputtered Bi film was hardly observed regardless of measuring temperature, whereas those of annealed were found to reach 30,000% at 4 K and 600% at 300 K respectively. The drastic change in MR after annealing is largely attributed to the significant grain growth decreasing grain boundary scattering as well as to the trigonal-axis oriented microstructures diminishing anisotropy scattering of moving electron. Our results demonstrate sputtered Bi thin film can be usable for spintronic devices by employing a suitable post annealing treatment. (Received March 29, 2004) |