High field magnetization of Tm2AlB6, an AlB 2-type analogue compound

Abstract

The high field magnetization of Tm2Al11B6 was measured up to 140 kOe. Tm2Al11B6 was previously observed to show an interesting magnetic field dependence wherein one of the two transitions, TN1, showed little magnetic field dependence from 20 kOe to 70 kOe in the specific heat. A kink in the high field magnetization at ∼3 K is observed even up to 140 kOe, indicating the antiferromagnetic-like nature of the transition, and the high field state's extreme stability (steep phase boundary) versus magnetic field. Even at the highest fields the saturation magnetization takes a small value (∼ 3.3 μB/Tm) only about half that expected for a trivalent thulium ion. It is likely that only one Tm ion among the two crystallographic sites in Tm2Al11B6 is ordering, while the other has a non magnetic singlet ground state. © 2010 IOP Publishing Ltd.