The Influence of Hydrogen on Structural and Magnetic Transformations in RMn2Hx Hydrides with Laves Phase C15 and C14 Structures—A Review

Abstract

Laves phases crystallize in simple structures and are very common intermetallic phases that can form from combinations of elements throughout the periodic table, giving a huge number of known examples. A special feature of AB2 or AB5 phases is the ability to absorb hydrogen. This study attempts to collect, systematize and summarize the knowledge about RMn2Hx (R: Tb, Gd, Ho, Dy, Er, Sm, Nd and Y) hydrides available in the literature that is mainly related to structural and magnetic transformations. Due to the enormous wealth of data, the analysis focused on hydrides with x < 4.5 H/f.u., i.e., hydrides obtained at relatively low pressure (less than a few bars). The hydrides obtained in this way can be treated as potential hydrogen stores, which undoubtedly accounts for their current attractiveness.