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) 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 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 an inorganic compound, which exhibits QTM at a single-ion level and magnetic order due to classical dipolar interaction.

Quasi One-Dimensional Ising-like Antiferromagnetism in the Rare-earth Perovskite Oxide TbScO$_3$

“…Broad continuum-like spinon excitations were observed for YbAlO 3 [8], while they are absent for DyScO 3 and TbScO 3 . Slow spin dynamics were observed in DyScO 3 [39], while this has not been found for YbAlO 3 and TbScO 3 . What is the underlying mechanism that causes the distinct physics for these three isostructural compounds?…”

“…Fig. 2(a) is the isothermal magnetization M (B) as a function of the applied field along the b axis with temperature ranging from 0.1 K to 2.5 K. We also checked if there was any slow dynamics persisting in this system, similar with the ob-servation in DyScO 3 [20,38,39]. As shown in Fig.…”

“…On the other hand, for DyScO 3 , all these terms that connect spin up and down are close to zero ( E 0∓ |S ± , S z |E 0± = 0). The spin-up moments can relax to the spin-down states by overcoming the large CEF energy barrier [42], and thus significant slow dynamics are observed [39]. Conversely, Tb is a non-Kramers ion, and the quasi-doublet state consists of two low-lying singlet states.…”