Magnetoresistance Anomalies in Ce-based Heavy Fermion Compounds

TL;DR

This study investigates magnetoresistance anomalies in Ce-based heavy fermion compounds through experimental measurements and analysis, revealing insights into magnetic phases and electron density effects near quantum critical points.

Contribution

It applies Yosida's theoretical approach to analyze magnetoresistance data, identifying additional contributions and characterizing magnetic phase diagrams in Ce compounds.

Findings

Identification of two additional contributions to magnetoresistance.

Estimation of local magnetic susceptibility from data.

Revelation of electron density of states renormalization near quantum criticality.

Abstract

The work presents experimental results of precision magnetoresistance dr(H,T) measurements obtained for canonical heavy fermion compounds CeAl2, CeAl3, CeCu6 and substitutional solid solutions CeCu6-xAux (x=0.1 and 0.2) and Ce(Al0.95M0.05)2 (M - Co, Ni). The research was performed in a wide range of temperatures (1.8-30K) and magnetic fields (up to 80 kOe). The data analysis indicates that the most consistent interpretation of magnetoresistance of both paramagnetic and magnetically ordered Ce-based systems with strong electron correlations can be obtained through the approach developed by K.Yosida (Phys.Rev., 107, 396(1957)) that considers charge carrier scattering on localized magnetic moments in metallic matrix. Within this approach local magnetic susceptibility hiloc(H,T0)=(1/H d(dr/r)/dH)1/2 has been estimated directly from the magnetoresistance data dr/r=f(H,T0). As a result, two additional contributions to magnetoresistance in Ce-based magnetic intermetallides have been established and classified. The procedure allowed to determine the peculiarities of magnetic phase ht diagram as well as to reveal the electron density of states renormalization effects in a wide vicinity of quantum critical point in the archetypal Ce-based systems with strong electron correlations.