Formation and magnetic properties of p-type icosahedral quasicrystals in Zn–Fe–Sc–L (L = Ho, Er, Tm) alloys

Abstract

Icosahedral quasicrystals containing heavy lanthanoids L, namely Ho, Er or Tm, have been discovered in the Zn₇₇Fe₇Sc_16–xL_x alloy systems. The solubility limit of the lanthanoid is approximately half of the Sc atoms. All these quasicrystals belong to p-type and are stable at approximately 973 K. The temperature dependence of the magnetic susceptibility of the Zn₇₇Fe₇Sc₈Tm₈ quasicrystal follows the Curie–Weiss law and exhibits spin-glass-like behaviour with a freezing temperature of 9 K. The Curie constants obtained by Curie–Weiss fit are larger than those calculated by the Lande g-factor of free Tm³⁺ ions based on Hund's rule, assuming all magnetization is caused by Tm atoms only. It is deduced that both Tm and Fe atoms exhibit magnetic moments. This is the first example of a stable icosahedral quasicrystal containing two types of magnetic atoms: Fe and the lanthanoids.

Acknowledgements

Thanks are due to the Research Center for Molecular-Scale Nanoscience, the Institute for Molecular Science for assistance in obtaining the experimental data of magnetism. We also thank Dr M. Fujiwara and N. Miyazaki for their cooperation. This work was partly supported by a Grant-in-Aid for the Scientific Research of Priority Areas ‘Panoscopic Assembling and High Ordered Functions for Rare Earth Materials’.