Ce${}_{3-x}$Mg${}_x$Co${}_9$: transformation of a Pauli paramagnet into a strong permanent magnet

Abstract

We report on the synthesis of single crystalline and polycrystalline samples of Ce${}_{3-x}$Mg${}_x$Co${}_9$ solid solution ($0\le x\lesssim 1.4$) and characterization of their structural and magnetic properties. The crystal structure remains rhombohedral in the whole composition range and Mg partially replaces Ce in the 6\textit{c} site of the CeCo${}_3$ structure. Ferromagnetism is induced by Mg substitutions starting as low as $x=0.18$ and reaching a Curie temperature as high as $450$\,K for $x=1.35$. Measurements on single crystals with $x=1.34$ and $T_{\text{C}}=440$\,K indicate an axial magnetic anisotropy with the anisotropy field of $6$\,T and a magnetization of $6$\,${\mu }_B/$f.u. at $300$\,K. Coercicity is observed in the polycrystalline samples consistent with the observed axial magnetic anisotropy. Our discovery of ferromagnetism with large axial magnetic anisotropy induced by substituting a rare-earth element by Mg is a very promising result in the search of inexpensive permanent-magnet materials and suggests other non-magnetic phases, similar to CeCo${}_3$, may also conceal nearby ferromagnetic phases.

Physical Review Applied 2018

References in corpus (1)

• Discovery of ferromagnetism with large magnetic anisotropy in ZrMnP and HfMnP