Large Magnetoresistance of Electrodeposited Single-Crystal Bismuth Thin Films

Single-crystal bismuth thin Þlms 1 to 20 micrometers thick were fabricated by electrodeposition and suitable annealing. Magnetoresistance up to 250 percent at 300 kelvin and 380,000 percent at 5 kelvin as well as clean Shubnikov—de Haas oscillations were observed, indicative of the high quality of these Þlms. A hybrid structure was also made that showed a large magnetoresistive effect of 30 percent at 200 oersted and a Þeld sensitivity of 0.2 percent magnetore-sistance per oersted at room temperature. Bismuth (Bi) is a semimetal with unusual electronic properties that result from its high-ly anisotropic Fermi surface, low carrier con-centrations, and small effective carrier mass-es m*. Because of its large Fermi wavelength and long carrier mean free path l (1), Bi has been extensively investigated for quantum transport and finite-size effects (2, 3). Th