Magnetic study of Tb(OH)3

Abstract

The thermal and magnetic properties of Tb(OH)3 have so far only been reported at liquid hydrogen and helium temperatures, no reports are available for any such measurements at higher temperatures. Measurements are now described on the magnetic susceptibilities of powdered samples and of the magnetic anisotropy of single crystals of Tb(OH)3 between 300 and 80K. The principal susceptibilities K/sub /// and Kperpendicular to have been fitted with the experimental results by varying the crystal-field parameters using a computer program. The parameters B20=198 cm-1, B40=-59 cm-1, B60=-45 cm-1 and B66=585 cm-1 give a better fit to the experimental values and differ slightly from those obtained previously. The authors have also calculated the zero-field susceptibility of Tb(OH)3 by a high-temperature series-expansion method around the critical temperature. The experimental and predicted values deviate because of the onset of a complex type of short-range ordering as the critical temperature is approached.