Achievement of promising cryogenic magnetocaloric performances in La_(1-x)Pr_(x)Fe_(12)B_(6)compounds

The magnetic refrigeration(MR)utilizing magnetocaloric effect(MCE)has been recognized as an environmentally friendly and energy efficiency technology.Here we presented the magnetic properties and MCE in Pr-doped La_(1-x)Pr_(x)Fe_(12)B_(6)(x=0.05-0.2)itinerant-electron metamagnetic(IEM)compounds.A small amount of Pr doping La site can greatly improve the peak values in the magnetic entropy change S_(M)(T)curves,especially under relatively low magnetic field changes(ΔH).Additionally,the peak temperature increases gradually and the magnetic hysteresis reduces gradually with increasing x.The observed MCE in present La_(1-x)Pr_(x)Fe_(12)B_(6)compounds is related to its field-induced first-ordered IEM transition.The peak values ofΔS_(M)for La_(1-x)Pr_(x)Fe_(12)B_(6)compounds reach 13.4,15.4,12.5 and 13.0 J/(kg K)at T_(C)~58,68,72and 89 K for x=0.05,0.10,0.15 and 0.2 under H of 0-7 T,respectively.The corresponding relative cooling power values are 462.3,480.7,372.4 and 375.7 J/kg.The present La_(1-x)Pr_(x)Fe_(12)B_(6)compounds could be good candidates for active MR application if the magnetic and thermal hysteresis can be further reduced.The present work indicates that the La Fe_(12)B_(6)-based material system could also exhibit promising magnetocaloric performances.