muSR in Ce_{1-x}La_xAl_3: anisotropic Kondo effect?

TL;DR

This study uses muSR experiments to investigate the magnetic properties of Ce_{1-x}La_xAl_3 alloys, finding evidence of disordered antiferromagnetism and challenging the idea of an anisotropic Kondo effect at the specific heat anomaly temperature.

Contribution

The paper provides experimental evidence that supports a magnetic transition over anisotropic Kondo behavior in Ce_{1-x}La_xAl_3 alloys.

Findings

Detection of disordered antiferromagnetism in both alloys

Oscillation frequency decreases with temperature in x=0.2

T* corresponds to a magnetic transition, not anisotropic Kondo effect

Abstract

Zero-field muSR experiments in the heavy-fermion alloys Ce_{1-x}La_xAl_3, x = 0 and 0.2, examine a recent proposal that the system exhibits a strong anisotropic Kondo effect. We resolve a damped oscillatory component for both La concentrations, indicative of disordered antiferromagnetism. For x = 0.2 the oscillation frequency decreases smoothly with increasing temperature, and vanishes at the specific heat anomaly temperature T* \approx 2.2 K. Our results are consistent with the view that T* is due to a magnetic transition rather than anisotropic Kondo behavior.