Vacancy-mediated fcc/bcc phase separation in Fe1-xNix ultrathin films

Article

关键词: NI;    FE;    DECOMPOSITION;    TEMPERATURE;    FE(110);    W(110);    MN;   

DOI  :  10.1103/PhysRevB.94.085402

来源: SCIE

【 摘 要 】

The phase separation occurring in Fe-Ni thin films near the Invar composition is studied by using high-resolution spectromicroscopy techniques and density functional theory calculations. Annealed at temperatures around 300 degrees C, Fe0.70Ni0.30 films on W(110) break into micron-sized bcc and fcc domains with compositions in agreement with the bulk Fe-Ni phase diagram. Ni is found to be the diffusing species in forming the chemical heterogeneity. The experimentally determined energy barrier of 1.59 +/- 0.09 eV is identified as the vacancy formation energy via density functional theory calculations. Thus, the principal role of the surface in the phase separation process is attributed to vacancy creation without interstitials.

【 授权许可】

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