Genesis of the anomalous Hall effect in CeAl2

The Hall coefficient R-H, resistivity rho, and Seebeck coefficient S of the CeAl2 compound with fast electron density fluctuations were studied in a wide temperature range (from 1.8 to 300 K). Detailed measurements of the angular dependences R-H(phi, T, H less than or equal to 70 kOe) were performed to determine contributions to the anomalous Hall effect and study the behavior of the anomalous magnetic R-H(am) and main R-H(a) components of the Hall signal of this compound with strong electron correlation. The special features of the behavior of the anomalous magnetic component R-H(am) were used to analyze the complex magnetic phase diagram H-T determined by magnetic ordering in the presence of strong spin fluctuations. An analysis of changes in the main contribution R-H(a) (H, T) to the Hall effect made it possible to determine the complex activation behavior of this anomalous component in the CeAl2 intermetallic compound. The results led us to conclude that taking into account spin-polaron effects was necessary and that the Kondo lattice and skew-scattering models were of very limited applicability as methods for describing the low-temperature transport of charge carriers in cerium-based intermetallic compounds. The effective masses and localization radii of manybody states in the CeAl2 matrix were estimated to be (55-90)m(0) and 6-10 Angstrom, respectively. The behaviors of the parameters R-H, S, and rho were jointly analyzed. The results allowed us to consistently describe the transport coefficients of CeAl2. (C) 2004 MAIK "Nauka/Interperiodica".