Cooling in rare-earth paramagnets at ultrahigh pulsed magnetic fields due to energy level crossing

摘要

Maxima of differential magnetic susceptibility are observed at 4.2 K in a pulsed field in the tetragonal paramagnets YbPO4 and PrVO4 at 280 and 45 T, respectively, caused by crossing of the energy levels of rare-earth ions. Different characters of the level interactions result in different types of magnetocaloric effect in the adiabatic regime. A theory of these phenomena is developed. (C) 2000 Published by Elsevier Science B.V. All rights reserved. [References: 4]