Magnetization Process of Haldane Materials TMNIN and NINAZ

Abstract

Magnetization measurements have been performed on the Haldane gap materials (CH 3 ) 4 NNi(NO 2 ) 3 (TMNIN) and Ni(C 3 H 10 N 2 ) 2 N 3 (ClO 4 ) (NINAZ) in pulsed high magnetic fields. TMNIN shows a typical magnetization profile of the Haldane material with the gap energy of 4.1 K. Quenching of the gap appears around 2.7 Tesla(T) and magnetic saturation is obtained above 30 T. In NINAZ, however, the quenching appears at around 30 T reflecting a large Haldane gap energy with the magnitude of 44.3 K.