Irregular Homogeneity Domains in Ternary Intermetallic Systems

Applied Sciences

Jean-Marc Joubert¹  Mohamed Andasmas²  Jean-Claude Crivello² 

[1] Chimie Métallurgique des Terres Rares (CMTR), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Centre National de la Recherche Scientifique (CNRS) Université Paris-Est Créteil, 2-8 rue Henri Dunant 94320 Thiais Cedex, France;

关键词: phase diagrams;    DFT;    Rietveld;    site occupancies;    homogeneity domains;   

DOI  :  10.3390/app5041570

来源: mdpi

【 摘 要 】

Ternary intermetallic A–B–C systems sometimes have unexpected behaviors. The present paper examines situations in which there is a tendency to simultaneously form the compounds AB_x, AC_x and BC_x with the same crystal structure. This causes irregular shapes of the phase homogeneity domains and, from a structural point of view, a complete reversal of site occupancies for the B atom when crossing the homogeneity domain. This work reviews previous studies done in the systems Fe–Nb–Zr, Hf–Mo–Re, Hf–Re–W, Mo–Re–Zr, Re–W–Zr, Cr–Mn–Si, Cr–Mo–Re, and Mo–Ni–Re, and involving the topologically close-packed Laves, χ and σ phases. These systems have been studied using ternary isothermal section determination, DFT calculations, site occupancy measurement using joint X-ray, and neutron diffraction Rietveld refinement. Conclusions are drawn concerning this phenomenon. The paper also reports new experimental or calculated data on Co–Cr–Re and Fe–Nb–Zr systems.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.