Crystal structures and magnetic properties of the BaAl4-type structure derivatives in Gd–Al–Ga system

• Published in: Journal of alloys and compounds 2013-11, Vol.576, p.114-120
• Main Authors: Belyavina, Nadezhda N., Babich, Mykola G., Markiv, Vasyl Ya, Nakonechna, Olesya I., Zakharenko, Mykola I.
• Format: Article
• Language: English
• Subjects: Aluminum; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Crystal structure; Exact sciences and technology; Gadolinium; Gallium; Intermetallic compounds; Magnetic properties; Magnetic properties and materials; Physics; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.04.086

•We study the crystal structure of GdAlxGa4−x compounds with 8–66at.% Ga.•Existing range of these compounds is fragmented into seven individual regions.•The effective magnetic moments have been calculated.•The excess magnetic moments are caused by the contribution of the non-4f electrons. The crystal structures of GdAlxGa4−x−v compounds (8–66at.% Ga, x=3.6–0.70, v=0–0.12) were studied by the X-ray diffraction methods (both single crystal and powder diffraction ones). Two new types of structure (monoclinic GdAl3.00Ga0.76 and orthorhombic GdAl2Ga2) were shown to be constructed of two distorted BaAl4-like fragments. Reasoning from the peculiarities of crystal structures, the whole existence region of the GdAlxGa4−x−v compounds is fragmented into seven narrow individual ones (seven compounds). At the temperature range 300–650K the GdAlxGa4−x−v alloys were shown to be paramagnets with magnetic moments decreasing from 8.07 to 7.84μB with Ga-content increasing.