Si segregation in polycrystalline Co2MnSi films with grain-size control

Hirohata, A.; Ladak, S.; Aley, N. P.; Hix, G. B.
December 2009
Applied Physics Letters;12/21/2009, Vol. 95 Issue 25, p252506
Academic Journal
In order to characterize the interface/surface properties of polycrystalline Co2MnSi Heusler alloy films, grain-size evolution with increasing annealing time has been investigated. Here, samples with nanometer-scale grains have been prepared by our specially-designed sputtering system in order to maximize the interface/surface area. Our well-controlled grains clearly show Si phase segregation. This Si phase becomes conductive near room temperature and may be responsible for the significant decrease in tunneling magnetoresistance previously reported by [Wang et al., Appl. Phys. Lett. 93, 122506 (2008)].


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