Exploration of structural,magnetic,and magnetocaloric characteristics of double perovskites HoRCoMnO_(6)(R=Ho,Gd,Eu or Nd)  

作　　者：O.El Oujihi L.H.Omari A.Hajji A.Tizliouine E.Dhahri 

机构地区：[1]LMPGI,High School of Technology,Hassan II University of Casablanca,B.P 8012 Oasis,Casablanca,Morocco [2]CEDoc,National High School of Electricity and Mechanics(ENSEM),Hassan II University of Casablanca,B.P 8118 Oasis,Casablanca,Morocco [3]LPMAT,Faculty of Sciences Ain Chock,Hassan II University of Casablanca,B.P 5366 Maarif,Casablanca,Morocco [4]Laboratoire Physique Appliquée,FacultéDes Sciences,Universitéde Sfax,B.P.1171,3000,Sfax,Tunisia

出　　处：《Journal of Rare Earths》2025年第4期743-751,I0004,共10页稀土学报(英文版)

摘　　要：A conventional solid-state process was used to synthesize the double perovskite materials HoRCoMnO_(6)(R=Ho,Gd,Eu,Nd).The structural properties of the compounds were investigated using X-ray powder diffraction(XRD).The results revealed that Ho_(2)CoMnO_(6) crystallizes in a monoclinic structure with the P2_(1)/n space group.In contrast,the other compounds HoRCoMnO_(6)(R=Gd,Eu,or Nd) exhibit an orthorhombic structure with the Pnma space group.As a result,the average crystallite size also changes as a function of rare-earth element doping.This investigation reveals that the magnetic properties of the compounds studied are significantly dependent on the doping elements.The Curie temperature T_C,for example,increases from 80 to 118℃ with the ionic radii of rare earths increasing.Furthermore,the study of the magnetocaloric effect(MCE) shows that the maximum of the entropy variation(-ΔS_M^(max)) increases from 4.97 to 6.06 J/(kg·K) under a magnetic field of 5 T with substitution by rare-earth ions.To examine the efficiency of MCE materials,the relative cooling power(RCP) was evaluated and is found to increase with increment of rare-earth radius till 406.69 J/kg for Nd.The mean entropy variation with tempe rature(TEC) was also studied.Due to their significant magnetocaloric performance,HoRCoMnO_(6)(noted as HRCMO) compounds(with R=Ho,Gd,Eu or Nd) could be good candidates for low-temperature magnetic cooling applications.

关 键 词：Double perovskite Structural propriety Magnetic characteristics Rare earth compounds Magneto-caloric effect 

分 类 号：O469[理学—凝聚态物理]