Interplay between disorder driven Non-Fermi-liquid behavior and magnetism in Ce0.24La0.76Ge compound

TL;DR

This study explores how disorder influences non-Fermi-liquid behavior and magnetism in Ce0.24La0.76Ge, revealing suppressed magnetic transitions and anomalous temperature dependencies linked to disordered 4f spins, with a field-induced crossover to magnetic order.

Contribution

It demonstrates the interplay between disorder-driven NFL behavior and magnetism in Ce-La germanide compounds, highlighting a crossover from NFL to magnetic states under magnetic field.

Findings

Suppression of antiferromagnetic transitions below 1.8 K in Ce0.24La0.76Ge

Observation of anomalous temperature dependencies indicating NFL behavior

Magnetic field induces a crossover from NFL to magnetic order

Abstract

In this work, we investigate the magnetic, heat capacity and electrical transport properties of Ce0.6La0.4Ge and Ce0.24La0.76Ge compounds. Our results show that two antiferromagnetic transitions (~ at 4.7 and 2.7 K) exhibited by Ce0.6La0.4Ge are suppressed below 1.8 K for Ce0.24La0.76Ge. Interestingly, for Ce0.24La0.76Ge, susceptibility, heat capacity and electrical resistivity vary with temperature as: T0.75, T0.5 and T1.6 respectively. The observation of such anomalous temperature variation suggests to the Non-Fermi-liquid (NFL) behavior due to the presence of disordered 4f spins due to Ce-site dilution. Under the application of magnetic field, it is noted that a crossover from the NFL to a magnetic state occurs around 2 Tesla, where, short-range correlations among the spins is prevalent due to the dominance of coupling between the magnetic moments via conduction electrons. Magnetoresistance scaling indicates that behavior of disorder driven NFL state is described by the dynamical mean field theory of the spin glass quantum critical point.