The GMR effect in annealed Co/Co2TiSn thin films

The giant magnetoresistance (GMR) effect of Co/Co2TiSn thin films with two magnet phases was observed in samples annealed in vacuum and N-2(10% H-2) g as atmospheres. The perpendicular magnetization curve of the films have the hysteresis loop of a typical bubble domain material. Various features of e lectrical resistivity at room temperature of the annealed films suggest GMR behavior. The resistivity decreases with increasing field and saturates at a field of around 2 kOe which is the same as in-plane saturation field fro m magnetization measurements. In the film annealed in N-2 gas, the magnetor esistivity, delta rho(H), is 1.43 x 10(-7) Omega cm and the GMR is 0.18%. I n the film annealed in vacuum, the delta rho(H) and GMR are about 3.3 x 10( -8) Omega cm and 0.12%, respectively. The GMR effect in annealed Co/Co2TiSn films indicates the scattering of spin polarized conduction electrons beca use of the antiparallel exchange coupling at the phase boundary between the two magnetic phases. The scattering process of conduction electrons at the phase boundary was modeled in relation to the magnetization process. (C) 2 000 American Institute of Physics. [S0021-8979(00)58308-X].