Anomalous charge transport in RB12 (R = Ho, Er, Tm, Lu)

High precision measurements of Hall RH(T) and Seebeck S(T) coefficients have been carried out for the first time on single crystals of rare earth dodecaborides RB12 (R = Ho, Er, Tm, Lu) at temperatures 1.8–300 K. Low temperature anomalies detected on the temperature dependencies of RH(T) and S(T) are associated with antiferromagnetic phase transitions in HoB12, ErB12 and TmB12 compounds. The observed discrepancy between the change of charge carriers' mobility and de-Gennes factor (g – 1)2 J(J + 1) (J – angular momentum of the 4f shell) in the set of HoB12–TmB12 allows us to conclude about the appreciable influence of spin fluctuations on the charge transport in these compounds with B12 atomic clusters. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)