A novel principle for cooling by adiabatic pressure application in rare-earth compounds

A novel principle for cooling by adiabatic pressure application in rare-ear th compounds is introduced. The principle is based on the occurrence of a p ressure-induced structural and/or magnetic phase transition where the point symmetry at the rare-earth site is changed involving a change of the degen eracy of the crystal-field ground state and/or a complete lifting of the de generacy of the crystal-field states by the Zeeman effect. Cooling can then be achieved under adiabatic application (or removal) of pressure as will b e demonstrated for the rare-earth compounds Pr1-xLaxNiO3 and CeSb. (C) 2000 Elsevier Science S.A. All rights reserved.