Physical properties and magnetic structure of TbRhIn5 intermetallic compound

TL;DR

This study investigates the magnetic and physical properties of the intermetallic compound TbRhIn5, revealing its high antiferromagnetic ordering temperature and magnetic structure through various experimental techniques and theoretical modeling.

Contribution

It provides the first detailed analysis of TbRhIn5's magnetic structure and properties, contrasting its high TN with expectations from de Gennes scaling and explaining it via CEF effects.

Findings

TbRhIn5 orders antiferromagnetically at 45.5 K

Magnetic structure has propagation vector (1/2 0 1/2) with moments along c-axis

Strong dipolar enhancements indicate high polarization of Tb 5d levels

Abstract

In this work we report the physical properties of the new intermetallic compound TbRhIn5 investigated by means of temperature dependent magnetic susceptibility, electrical resistivity, heat-capacity and resonant x-ray magnetic diffraction experiments. TbRhIn5 is an intermetallic compound that orders antiferromagnetically at TN = 45.5 K, the highest ordering temperature among the existing RRhIn5 (1-1-5, R = rare earth) materials. This result is in contrast to what is expected from a de Gennes scaling along the RRhIn5 series. The X-ray resonant diffraction data below TN reveal a commensurate antiferromagnetic (AFM) structure with a propagation vector (1/2 0 1/2) and the Tb moments oriented along the c-axis. Strong (over two order of magnitude) dipolar enhancements of the magnetic Bragg peaks were observed at both Tb absorption edges LII and LIII, indicating a fairly high polarization of the Tb 5d levels. Using a mean field model including an isotropic first-neighbors exchange interaction J(R-R) and the tetragonal crystalline electrical field (CEF), we were able to fit our experimental data and to explain the direction of the ordered Tb-moments and the enhanced TN of this compound. The evolution of the magnetic properties along the RRhIn5 series and its relation to CEF effects for a given rare-earth is discussed.