Enhanced interlafer coupling and magnetoresistance ratio in Fe ₃Si/FeSi₂ superlattlces

[Fe₃Si/FeSi₂]₂₀ superlattices were prepared on Si(111) at an elevated substrate temperature of 300°C, and the magnetoresistance ratio and interlayer coupling strengths were enhanced by approximately 100 and 34%, respectively, as compared to those of superlattices deposited at room temperature. While the elevated substrate temperature degraded the interface sharpness, the crystalline orientation and the crystallinity of the Fe₃Si layers were apparently enhanced. The latters strongly influence on the interlayer coupling and the magnetoresistance ratio. This implies that quantum well states are tightly formed under the well-ordered crystalline planes, and the spin diffusion lengths are improved due to the enhanced crystallinity.