Rare-earth(RE)rich intermetallics crystallizing in orthorhombic Ho_(6)Co_(2)Ga-type crystal structure exhibit peculiar magnetic properties that are not widely reported for their magnetic ordering,order of magnetic pha...Rare-earth(RE)rich intermetallics crystallizing in orthorhombic Ho_(6)Co_(2)Ga-type crystal structure exhibit peculiar magnetic properties that are not widely reported for their magnetic ordering,order of magnetic phase transition,and related magnetocaloric behavior.By tuning the type of RE element in RE_(6)Co_(2)Ga(RE=Ho,Dy or Gd)compounds,metamagnetic anti-to-paramagnetic(AF to PM)phase transitions could be tuned to ferro-to-paramagnetic(FM to PM)phase transitions.Furthermore,the FM ground state for Gd_(6)Co_(2)Ga is confirmed by density functional theory calculations in addition to experimental observations.The field dependence magnetocaloric and Banerjee’s criteria demonstrate that Ho_(6)Co_(2)Ga and Dy_(6)Co_(2)Ga undergo a first-order phase transition in addition to a second-order phase transition,whereas only the latter is observed for Gd_(6)Co_(2)Ga.The two extreme alloys of the series,Ho_(6)Co_(2)Ga and Gd_(6)Co_(2)Ga,show maximum isothermal entropy change(|ΔS_(iso)^(max)(5T)|)of 10.1 and 9.1 J kg^(-1)K^(-1)at 26 and 75 K,close to H_(2)and N_(2)liquefaction,respectively.This outstanding magnetocaloric effect performance makes the RE6 Co_(2)Ga series of potential for cryogenic magnetic refrigeration applications.展开更多
基金the National Natural Science Foundation of China(52071197)the Science and Technology Commission of Shanghai Municipality(19ZR1418300 and 19DZ2270200)+3 种基金AEI/FEDER-UE(PID2019-105720RB-I00)US/JUNTA/FEDER-UE(US-1260179)Consejería de Economía,Conocimiento,Empresas y Universidad de la Junta de Andalucía(P18-RT-746)the support provided by China Scholarship Council(CSC)of the Ministry of Education,China(202006890050)。
文摘Rare-earth(RE)rich intermetallics crystallizing in orthorhombic Ho_(6)Co_(2)Ga-type crystal structure exhibit peculiar magnetic properties that are not widely reported for their magnetic ordering,order of magnetic phase transition,and related magnetocaloric behavior.By tuning the type of RE element in RE_(6)Co_(2)Ga(RE=Ho,Dy or Gd)compounds,metamagnetic anti-to-paramagnetic(AF to PM)phase transitions could be tuned to ferro-to-paramagnetic(FM to PM)phase transitions.Furthermore,the FM ground state for Gd_(6)Co_(2)Ga is confirmed by density functional theory calculations in addition to experimental observations.The field dependence magnetocaloric and Banerjee’s criteria demonstrate that Ho_(6)Co_(2)Ga and Dy_(6)Co_(2)Ga undergo a first-order phase transition in addition to a second-order phase transition,whereas only the latter is observed for Gd_(6)Co_(2)Ga.The two extreme alloys of the series,Ho_(6)Co_(2)Ga and Gd_(6)Co_(2)Ga,show maximum isothermal entropy change(|ΔS_(iso)^(max)(5T)|)of 10.1 and 9.1 J kg^(-1)K^(-1)at 26 and 75 K,close to H_(2)and N_(2)liquefaction,respectively.This outstanding magnetocaloric effect performance makes the RE6 Co_(2)Ga series of potential for cryogenic magnetic refrigeration applications.
