Effects of hydrogen on the magnetic properties of TiZrNi quasicrystals

Abstract

The magnetic properties of hydrogenated metastable TiZrNi quasicrystals and their structures were studied. After hydrogenation, the quasi-lattice constants uniformly increased from 5.12 to 5.40 with a narrower peak width in X-ray diffraction, suggesting that hydrogen atoms diffuse homogeneously in different pieces of the metallic ribbon samples. The magnetization values measured by using a superconducting quantum interference device (SQUID) revealed that the magnetic susceptibilities of the hydrogenated quasicrystals strongly depended on the temperature so that the enhanced magnetic coercivities at low temperatures (< 9 K) were the result of a combination of hydrogen and temperature while the reduced magnetization values at temperatures above 9 K were attributed to the structural factor rather than the temperature. In fact, hydrogen contributes to the significant decrease in the magnetization values from 0.0236 to 0.0163 emu/g at room temperature. The reasons for the decreased magnetization after hydrogenation are understood to be the reduced interactions of magnetic moments between Ni atoms induced by the lattice expansion after hydrogen absorption.