Slow spin dynamics and quantum tunneling of magnetization in the dipolar antiferromagnet DyScO3

Abstract

We present a comprehensive study of static and dynamic magnetic properties in the Ising-like dipolar antiferromagnet (AFM) DyScO3 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∗=10K. Below TN=3.2K, DyScO3 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 Dy3+ moments, reproduce essential features of the magnetic behavior of DyScO3. We demonstrate that DyScO3 represents a rare example of an inorganic compound, which exhibits QTM at a single-ion level and magnetic order due to classical dipolar interaction.