Giant low-field magnetocaloric effect in EuTi1 − xNbxO3 (x = 0.05, 0.1, 0.15, and 0.2) compounds*

Abstract

The magnetic properties and magnetocaloric effect (MCE) of EuTi1 − x Nb x O3 (x = 0.05, 0.1, 0.15, and 0.2) compounds are investigated. Owing to electronic doping, parts of Ti ions are replaced by Nb ions, the lattice constant increases and a small number of Ti4+ (3d0) ions change into Ti3+ (3d1). It is the ferromagnetism state that is dominant in the derivative balance. The values of the maximum magnetic entropy change ( − Δ S M max ) are 10.3 J/kg · K, 9.6 J/kg · K, 13.1 J/kg · K, and 11.9 J/kg · K for EuTi1 − x Nb x O3 (x = 0.05, 0.1, 0.15, and 0.2) compounds and the values of refrigeration capacity are 36, 33, 86, and 80 J/kg as magnetic field changes in a range of 0 T–1 T. The EuTi1 − x Nb x O3 (x = 0.05, 0.1, 0.15, and 0.2) compounds with giant reversible MCE are considered as a good candidate for magnetic refrigerant working at low-temperature and low-field.