Magnetoresistance Scaling and the Anisotropy of Charge Carrier Scattering in the Paramagnetic Phase of Ho0.8Lu0.2B12 Cage Glass.

The transverse magnetoresistance of Ho0.8Lu0.2B12 dodecaboride with a cage glass structure is studied at low (2210 K) temperatures. It is demonstrated that the isotropic negative magnetoresistance in this antiferromagnet is dominant within the broad temperature range near TN K. This contribution to the total magnetoresistance is due to the scattering of charge carriers by nanoclusters formed by ³⁺ ions, and it can be scaled in the = f((²effH²/T²) representation. It is found that the magnetoresistance anisotropy above (about 15% at 80 kOe) is due to the positive contribution, which achieves maximum values at the magnetic field direction close to H [001]. The anisotropy of the charge carrier scattering is interpreted in terms of the cooperative dynamic JahnnTeller effect at B 12 clusters. [ABSTRACT FROM AUTHOR]