Interplay between disorder-driven non-Fermi-liquid behavior and magnetism in the Ce_0.24La_0.76Ge compound

School of Basic Sciences, Indian Institute of Technology Mandi - Mandi 175005, Himachal Pradesh, India

^(a) kaustav@iitmandi.ac.in

Received: 7 March 2019
Accepted: 7 June 2019

Abstract

In this work, we investigate the magnetic, heat capacity and electrical transport properties of the Ce_0.6La_0.4Ge and Ce_0.24La_0.76Ge compounds. Our results show that two antiferromagnetic transitions (∼ at 4.7 and 2.7 K) exhibited by Ce_0.6La_0.4Ge are suppressed below 1.8 K for Ce_0.24La_0.76Ge. Interestingly, for Ce_0.24La_0.76Ge, susceptibility, heat capacity and electrical resistivity vary with temperature as T^0.75, T^0.5 and T^1.6, respectively. The observation of such anomalous temperature variation suggests 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 are prevalent due to the dominance of coupling between the magnetic moments via conduction electrons. Magnetoresistance scaling indicates that the behavior of a disorder-driven NFL state is described by the dynamical mean-field theory of the spin glass quantum critical point.