Magnetic properties and magnetocaloric effect in Dy100-xYx solid solutions

Sergey Taskaev,Dmitriy Zherebtsov,Vladimir Khovaylo,Maxim Ulyanov,Marina Kononova,Daniil Plakhotskiy,Anastasiya Basharova,Zhang Hu,Dmitriy Bataev,Mikhail Bogush

doi:10.1063/9.0000191

Abstract

Dysprosium possesses the highest magnetic moment among the rare-earth elements and undergoes a second-order magnetic phase transition to a complex helical antiferromagnetic ordering at Néel temperature TN = 180 K which is followed by a transformation to the ferromagnetic ordering at a lower temperature. Superior magnetic properties and tunability of the magnetic phase transition temperatures make Dy and its solid solutions perspective for the use in technology of magnetic refrigeration at cryogenic temperatures, specifically for the liquefaction of natural gases. In this work we report on the evolution of magnetic properties in solid solutions of Dy100-xYx (x = 0 – 15). It was found that the dilution of Dy magnetic subsystem by a non-magnetic Y has rather a weak impact on the magnetization saturation, which decreases from Ms ∼280 A⋅m2/kg in the x = 0 sample to Ms ∼259 A⋅m2/kg in the x = 15 sample. As a consequence, the isothermal magnetic entropy change was found to decrease slightly in the series of Dy100-xYx (x = 0 – 15) solid solutions.

Highlights

Magnetic cooling technology based on magnetocaloric effect (MCE) has been intensively discussed as one of the promising technologies for the gas liquefaction
Since the dilution of dysprosium with paramagnetic atoms of yttrium will decrease the effective magnetic moment of the solid solution, for our study we selected samples with a low yttrium content x = 0, 5, 10, and 15 at%. In this case one can expect to observe a magnetocaloric effect close to the MCE of pure dysprosium while temperatures of the magnetic transitions should decrease due to weakening of exchange interactions
An example of X-ray structural and phase analyzes (XRD) pattern and its analysis by the Rietveld method for the studied solid solutions is shown in Fig. 1 for the case of the Dy90Y10 sample

Summary

Introduction

Magnetic cooling technology based on magnetocaloric effect (MCE) has been intensively discussed as one of the promising technologies for the gas liquefaction.1,2 This novel approach for the natural gases liquefaction has attracted growing attention due to the development of superconducting magnets which can generate strong magnetic fields. We present the results of a study of the magnetic properties of solid solutions Dy100-xYx (x = 5, 10, 15).

Results

Conclusion