Anomalies of magnetoresistance in Ce-based heavy fermion compounds

Magnetoresistance Delta rho(H, T) of several heavy-fermion compounds, CeAl2, CeAl3 and CeCu6, substitutional solid solutions with quantum critical behavior CeCu6-xAux (x = 0.1, 0.2) and alloys with magnetic ground state Ce(Al1-xMx)(2) (M = Co, Ni, x <= 0.8) was studied in a wide range of temperatures (1.8-40 K) in magnetic fields up to 80 kOe. It was shown that a consistent interpretation of the field dependences of the resistance for both non-magnetic and magnetically ordered cerium-based intermetallic compounds with strong electron correlations can be achieved within the framework of an approach that accounts for scattering of charge carriers by localized magnetic moments in a metal matrix. Within this approach, three different components of the magnetoresistance of cerium intermetallic compounds were identified: the negative Brillouin contribution proportional to the local magnetization (-Delta rho/rho similar to M-loc(2)), the alternating linear contribution (Delta rho/rho similar to H) and the magnetic component, saturating in magnetic fields below 15 kOe. In the framework of the Yosida model for the cerium alloys under study, estimates of the local magnetic susceptibility chi(loc)(H, T-0) were obtained from the magnetoresistance data. Numerical differentiation of the magnetoresistance with respect to the magnetic field and analysis of the obtained d(Delta rho/rho)/dH = f(H, T) dependences allowed us to reconstruct the H-T magnetic phase diagrams of the strongly correlated electron systems under study as well as to examine the effects of spin polarization and renormalization of the electronic states on charge transport both in the regime of quantum critical behavior and in the magnetically ordered state. (C) 2015 AIP Publishing LLC.