Size-induced changes of structural, magnetic and magnetocaloric properties of La0.7Ca0.2Ba0.1MnO3

Abstract

The particle size effects on the structural, magnetic and magnetocaloric properties of La 0.7 Ca 0.2 Ba 0.1 MnO 3 (LCBMO) manganites have been studied systematically. It is found that the sintering temperature could affect the micro-structures and the magnetic properties of these compounds intensively. The variations in the magnetic properties as a function of the particle size may be attributed to the local lattice distortion. With increase in the particle size, the Griffiths-phase-like behavior of susceptibility around the paramagnetic region is gradually suppressed. Furthermore, the maximum magnetic entropy change − Δ S M m a x gradually increases with increase in the particle size. For the sample with the largest particle size (7600 nm), the values of − Δ S M m a x were approximately 5.95 and 3.82 J/kg K with the magnetic field changes Δ Н =45 and 20 kOe, respectively. The relative cooling power (RCP) exhibits the non-monotonic dependence on the particle size. The maximum values of RCP could reach 239.6 and 102.9 J/kg with Δ Н =45 and 20 kOe, respectively, indicating LCBMO manganites could be promising candidates for the refrigerant materials of magnetic refrigerators.