Cooling by adiabatic pressure application in Pr1−xLaxNiO3

Abstract

A novel principle for cooling by adiabatic pressure application in the mixed crystalline compound Pr1−xLaxNiO3 is described and experimentally verified. Cooling occurs in the vicinity of the structural phase transition where the electronic ground state of the Pr3+ ions changes from a singlet to a doublet state. By properly choosing the La concentration x, the cooling effect can be achieved down to some 100 mK. Furthermore, Pr1−xLaxNiO3 can be used for second and third stage cooling down to the μK region by classical paramagnetic and nuclear demagnetization techniques, respectively.