Slow spin dynamics and quantum tunneling of magnetization in the dipolar antiferromagnet DyScO$_3$

TL;DR

This study investigates the magnetic properties of DyScO$_3$, revealing a transition from thermal activation to quantum tunneling of magnetization at 10 K, with complex low-temperature magnetic behavior explained by dipolar interactions.

Contribution

It provides the first detailed experimental and theoretical analysis of quantum tunneling and dipolar-driven magnetic order in DyScO$_3$, an inorganic compound.

Findings

Quantum tunneling of magnetization occurs below 10 K.

DyScO$_3$ exhibits antiferromagnetic order below 3.2 K.

Dipolar interactions explain key magnetic behaviors.

Abstract

We present a comprehensive study of static and dynamic magnetic properties in the Ising-like dipolar antiferromagnet (AFM) DyScO$_3$\ by means of DC and AC magnetization measurements supported by classical Monte-Carlo calculations. Our AC-susceptibility data show that the magnetic dynamics exhibit a clear crossover from an Arrhenius-like regime to quantum tunneling of magnetization (QTM) at $T^* = 10$ K. Below $T_{\mathrm{N}} = 3.2$ K DyScO$_3$ orders in an antiferromagnetic $GxAy$-type magnetic structure and the magnetization dynamics slow down to the minute timescale. The low-temperature magnetization curves exhibit complex hysteretic behavior, which depends strongly on the magnetic field sweep rate. We demonstrate that the low-field anomalies on the magnetization curve are related to the metamagnetic transition, while the hysteresis at higher fields is induced by a strong magnetocaloric effect. Our theoretical calculations, which take into account dipolar interaction between Dy$^{3+}$ moments, reproduce essential features of the magnetic behavior of DyScO$_3$. We demonstrate that DyScO$_3$ represents a rare example of inorganic compound, which exhibits QTM at a single-ion level and magnetic order due to classical dipolar interaction.