Magnetocrystalline anisotropy in RAu_{2}Ge_{2} (R = La, Ce and Pr) single crystals

TL;DR

This study investigates the magnetic anisotropy, electronic properties, and crystal electric field effects in single crystals of RAu_{2}Ge_{2} (R = La, Ce, Pr), revealing antiferromagnetic ordering, anisotropic Fermi surfaces, and specific heat contributions.

Contribution

It provides detailed magnetic, electronic, and thermal characterization of RAu_{2}Ge_{2} compounds, including a crystal electric field level scheme and insights into Kondo interactions.

Findings

Ce and Pr compounds show antiferromagnetic order with specific Néel temperatures.

CeAu_{2}Ge_{2} exhibits a spin-flip metamagnetic transition.

LaAu_{2}Ge_{2} displays anisotropic Fermi surface and Einstein heat capacity contribution.

Abstract

Anisotropic magnetic properties of single crystalline RAu_{2}Ge_{2} (R = La, Ce and Pr) compounds are reported. LaAu_{2}Ge_{2} exhibit a Pauli-paramagnetic behavior whereas CeAu_{2}Ge_{2} and PrAu_{2}Ge_{2} show an antiferromagnetic ordering with N\grave{e}el temperatures T_{N} = 13.5 and 9 K, respectively. The anisotropic magnetic response of Ce and Pr compounds establishes [001] as the easy axis of magnetization and a sharp spin-flip type metamagnetic transition is observed in the magnetic isotherms. The resistance and magnetoresistance behavior of these compounds, in particular LaAu_{2}Ge_{2}, indicate an anisotropic Fermi surface. The magnetoresistivity of CeAu_{2}Ge_{2} apparently reveals the presence of a residual Kondo interaction. A crystal electric field analysis of the anisotropic susceptibility in conjunction with the experimentally inferred Schottky heat capacity enables us to propose a crystal electric field level scheme for Ce and Pr compounds. For CeAu_{2}Ge_{2} our values are in excellent agreement with the previous reports on neutron diffraction. The heat capacity data in LaAu_{2}Ge_{2} show clearly the existence of Einstein contribution to the heat capacity.