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

Abstract

The transverse magnetoresistance of Ho_0.8Lu_0.2B₁₂ dodecaboride with a cage glass structure is studied at low (2–10 K) temperatures. It is demonstrated that the isotropic negative magnetoresistance in this antiferromagnet is dominant within the broad temperature range near T_N ≈ K. This contribution to the total magnetoresistance is due to the scattering of charge carriers by nanoclusters formed by Но³⁺ ions, and it can be scaled in the ρ = f(μ²_effH²/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 Jahn−Teller effect at В12 clusters.