ScholarWorks@숙명여자대학교

초록

The structural properties and magnetic phase stability of Fe(x)Pt(1-x) alloys in L1(2) crystal structure in bulk as well as thin film on Pt (110) substrate are studied by means of the highly precise full-potential linearized augmented plane-wave method within generalized gradient approximation. The antiferromagnetic (AFM) phase is found to be preferred over the ferromagnetic (FM) phase for FePt3 bulk alloy in agreement with experiment while FexPt(1-x), where x=0.25 and 0.5 with a film thickness smaller than 0.5 nm, favor the FM phase. The total energy calculation assuming pseudomorphic strain reveals that the AFM preference for bulk is maintained in wide range of tetragonal distortion up to the value of 22% reached by the surface relaxation of thin film, implying that the magnetic configuration change from AFM to FM at the thin film surface is originated in rather complex surface effects beyond the structural relaxation. The FM preference of thin film is predicted to fast suppress as the film thickness increases and finally the AFM preference is recovered for the film thickness of five atomic layers. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3057775]

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