PHONON MODES AND VIBRATIONAL ENTROPY OF MIXING IN FE-CR

Article

关键词: SPINODAL DECOMPOSITION;    ALLOYS;    PHASE;    SCATTERING;    SYSTEM;    MOSSBAUER;    CHROMIUM;   

DOI  :  10.1103/PhysRevB.52.3280

来源: SCIE

【 摘 要 】

Results from neutron inelastic-scattering experiments on Fe, Cr, and three bcc Fe-Cr alloys were analyzed with a Born-von Karmin model to obtain phonon density-of-states (DOS) curves. We compared the phonon DOS of the bce Fe-Cr alloys to the composite phonon DOS from appropriate fractions of the phonon DOS of the pure metals Fe and Cr. In the high-temperature limit, we obtained the vibrational entropy of mixing of Fe and Cr to be 0.141, 0.201, and 0.214 k(B)/atom for alloys of Fe70Cr30, Fe53Cr47, and Fe30Cr70, respectively, with the disordered solid solution having the larger vibrational entropy. Some expected effects of vibrational entropy on the chemical unmixing transformation in Fe-Cr are discussed.

【 授权许可】

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