Tuning the crystalline electric field and magnetic anisotropy along the CeCuBi$_{2-x}$Sb$_{x}$ series

TL;DR

This study investigates how the crystalline electric field and magnetic anisotropy evolve in the CeCuBi$_{2-x}$Sb$_{x}$ series, revealing their impact on magnetic properties and potential superconductivity through comprehensive experimental and modeling approaches.

Contribution

It provides a detailed analysis of the CEF evolution and magnetic anisotropy in CeCuBi$_{2-x}$Sb$_{x}$, combining experimental data with a mean field model to understand magnetic behavior.

Findings

Magnetic easy axis changes along the series.

CEF parameters vary systematically with composition.

Potential implications for Kondo physics and superconductivity.

Abstract

We have performed X-ray powder diffraction, magnetization, electrical resistivity, heat capacity and inelastic neutron scattering (INS) to investigate the physical properties of the intermetallic series of compounds CeCuBi$_{2-x}$Sb$_{x}$. These compounds crystallize in a tetragonal structure with space group $P4/nmm$ and present antiferromagnetic transition temperatures ranging from 3.6 K to 16 K. Remarkably, the magnetization easy axis changes along the series, which is closely related to the variations of the tetragonal crystalline electric field (CEF) parameters. This evolution was analyzed using a mean field model, which included anisotropic nearest-neighbor interactions and the tetragonal CEF Hamiltonian. The CEF parameters were obtained by fitting the magnetic susceptibility data with the constraints given by the INS measurements. Finally, we discuss how this CEF evolution can affect the Kondo physics and the search for a superconducting state in this family.