Magnetic anomalies in single crystalline Tb5Si3

TL;DR

This study investigates the magnetic properties of single crystalline Tb5Si3, revealing anisotropic behavior, multiple magnetic features near 70 K, and distinct magnetoresistance steps depending on magnetic field orientation, highlighting its complex magnetic nature.

Contribution

First detailed single-crystal magnetic and magnetoresistance analysis of Tb5Si3, uncovering anisotropic magnetic behavior and multiple field-induced steps not observable in polycrystalline samples.

Findings

Magnetic behavior is strongly anisotropic with an easy axis along the basal plane.

Multiple magnetic features observed near 70 K.

Distinct magnetoresistance steps depend on magnetic field orientation.

Abstract

The polycrystalline form of the compound, Tb5Si3, crystallizing in Mn5Si3-type hexagonal structure, which was earlier believe to order antiferromagnetically below 69 K, has been recently reported by us to exhibit interesting magnetoresistance (MR) anomalies. In order to understand the magnetic anomalies of this compound better, we synthesized single crystals of this compound and subjected them to intense magnetization and MR studies. The results reveal that the magnetic behavior is strongly anisotropic as the easy axis is along a basal plane. There appear to be multiple magnetic features in the close vicinity of 70 K. In addition, there are multiple steps in isothermal magnetization (which could not be resolved in the data for polycrystalline data) for magnetic-field (H) along a basal plane. The sign of MR is positive in the magnetically ordered state, and, interestingly, the magnitude dramatically increases at the initial step for H parallel to basal plane, but decreases at subsequent steps as though the origin of these steps are different. However, for the perpendicular orientation (H || [0 0 0 1]), there is no evidence for any step either in M(H) or in MR(H). These results establish this compound is an interesting magnetic material.