Magnetoresistance Anisotropy and Magnetic H-T Phase Diagram of Tm0.996Yb0.004B12.

The antiferromagnetic ground state has been studied by transverse magnetoresistance, heat capacity and magnetization measurements, which were carried out on high quality single crystals of Tm0:996Yb0:004B12 dodecaboride in strong magnetic fields at liquid helium temperatures. Both antiferromagnetic-paramagnetic (AFP) and spin-orientation (AF1-AF2) phase transitions have been observed, and allowed to construct a complicated magnetic H-T phase diagram for this compound. Strong magnetoresistance anisotropy was found both in AF states (ρ(H∥[110])/ρ(H∥[111]) ~ 1:2 at H ~ 20 kOe) and at the critical field of AF-P transition (HN[100]/HN[111] ~ 1:25) in this magnetic metal with a simple fcc crystal structure. [ABSTRACT FROM AUTHOR]