Anomalous Magnetizations in Single Crystalline SrCu_<b>2</b>(BO_<b>3</b>)_<b>2</b>

Abstract

The magnetic properties of a two-dimensional spin-gap compound SrCu 2 (BO 3 ) 2 , realizing the Shastry-Sutherland model, were investigated using high-quality single crystals. The analysis of the temperature-dependent magnetic susceptibility revealed a spin gap of 34 K. The magnetization curve at 0.4 K possibly has, in addition to the already established one-quarter and one-eighth plateaux, another quantized plateau at one-tenth of the full Cu moment, which is one of the plateaux predicted by Miyahara and Ueda.