A study of CsCl type intermediate phases involving rare earth elements

• Main Author: Chao, Chang-Chih
• Format: Others
• Published: 1965
• Online Access: https://thesis.library.caltech.edu/3451/1/Chao_c_1965.pdf; Chao, Chang-Chih (1965) A study of CsCl type intermediate phases involving rare earth elements. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/EKPF-2Q83. https://resolver.caltech.edu/CaltechETD:etd-09112002-171500 <https://resolver.caltech.edu/CaltechETD:etd-09112002-171500>

This thesis presents the results of a systematic study of CsCl type phases in binary alloys of rare earth elements with other metals. Thirty-nine new phases of this type have been found. The linear variation of the lattice parameter of CsCl phases with the trivalent ionic radius of the rare earth metal previously established for a limited number of alloys, has been extended to seventy-nine phases. This linear relationship leads to some interesting qualitative arguments on the ionic size of the non-rare earth element in these phases. The electrical resistivities of nineteen CsCl type phases of rare earths with copper, silver and gold were measured between 4.2 [degrees] K and about 260 [degrees] K. With the exception of the yttrium-silver phase, all others exhibited an anomaly in the resistivity-temperature curve which is attributed to an antiferromagnetic transition. This conclusion is confirmed by previously published results of neutron diffraction experiments and magnetic susceptibility measurements. A qualitative interpretation of the resistivity results based on the indirect exchange interaction between the ions of the same type (magnetic or non-magnetic) and between the ions of the different type (magnetic and non-magnetic) is proposed.