Anisotropic electron spin resonance of YbIr2Si2

TL;DR

This study investigates the anisotropic electron spin resonance in YbIr2Si2, revealing unexpected intensity variations and intrinsic basal plane anisotropy, advancing understanding of heavy fermion materials' magnetic properties.

Contribution

It provides detailed ESR measurements on YbIr2Si2, uncovering anisotropic behaviors and intrinsic sample properties not previously documented.

Findings

ESR intensity variation is smaller than predicted by g-factor anisotropy

Weak basal plane anisotropy observed in ESR parameters

Intrinsic sample property inferred from anisotropy analysis

Abstract

A series of electron spin resonance (ESR) experiments were performed on a single crystal of the heavy fermion metal YbIr2Si2 to map out the anisotropy of the ESR-intensity I_ESR which is governed by the microwave field component of the g-factor. The temperature dependencies of I_ESR(T) and g(T) were measured for different orientations and compared within the range 2.6K \le T \le 16K. The analysis of the intensity dependence on the crystal orientation with respect to both the direction of the microwave field and the static magnetic field revealed remarkable features: The intensity variation with respect to the direction of the microwave field was found to be one order of magnitude smaller than expected from the g-factor anisotropy. Furthermore, we observed a weak basal plane anisotropy of the ESR parameters which we interpret to be an intrinsic sample property.