High Magnetic Field Study of Chromium Trimer Complexes below 1 K

Abstract

Magnetizations of two trinuclear chromium salts are measured in pulsed magnetic fields up to 350 kOe. The experiment is done below 1 K using a 3 He cryostat arranged in a large-bore magnet of 6 cm in diameter. In Cr-propionate, the ground state crossover from S =1/2 to S =3/2 is observed at 272 kOe as a stepwise increase in the magnetization curve. The measurement in Cr-acetate at 0.6 K shows that the increase consists of two steps at 276 kOe and 314 kOe corresponding to two inequivalent sites of magnetic trimers in this compound. The magnitudes of the intra- and inter-trimer exchange interactions are discussed.