镝掺杂钙钛矿锰氧化物Gd_(0.67)Ca_(0.33)MnO_(3)的磁性和磁卡效应  

Magnetic Properties and Magnetocaloric Effects of Dysprosium-doped Perovskite Manganese Oxide Gd_(0.67)Ca_(0.33)MnO_(0.3)

作　　者：陈红伟 赵晶 金香[1] 邢茹[1] 周敏[1] 赵建军[1] Chen Hongwei;Zhao Jing;Jin Xiang;Xing Ru;Zhou Min;Zhao Jianjun(Key Laboratory of Magnetism and Magnetic Materials at Universities of Inner Mongolia,Baotou Teachers'College,Baotou 014030,China)

机构地区：[1]包头师范学院物理科学与技术学院,内蒙古自治区高等学校磁学与磁性材料重点实验室,内蒙古包头014030

出　　处：《中国稀土学报》2023年第6期1084-1093,I0002,共11页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(11164019,51562032,61565013);内蒙古自治区硕士研究生科研创新资助项目(S20191190Z)资助。

摘　　要：借助传统的固相反应法制备了多晶系列样品Gd_(0.67-x)Dy_xCa_(0.33)Mn O_(3)(x=0,0.05,0.15),探究了Dy掺杂后对该系列样品磁性和磁卡效应的影响。研究结果表明:该系列样品呈现良好的单相性,均是立方钙钛矿结构,空间群为Pbnm;3个样品的铁磁性减弱、反铁磁性增强,并且Dy掺杂后系统内长程铁磁有序增强,形成了AFM团簇;通过该系列样品的临界行为分析,表明该系列样品均与平均场模型拟合较好;通过Arrott曲线和重标定曲线,发现母相和掺杂样品x=0.05,0.15均经历了一级相变到二级相变的过渡阶段;3个样品外加磁场为5 T的最大磁熵变值分别为1.53,1.44,1.40 J·kg^(-1)·K^(-1)。Polycrystalline samples Gd_(0.67)Ca_(0.33)MnO_(3)(x=0,0.05,0.15)were prepared by the traditional solid-phase reaction method.The influence of Dy doping on the magnetism and magnetocaloric effects of this series of samples were investigated.The research results show that the series of samples exhibit good single-phase properties,all of which were cubic perovskite structures with a space group of Pbnm.The ferromagnetism of the three samples is weakened,the antiferromagnetism is enhanced,and the long-range ferromagnetic order in the system is enhanced after Dy doping,AFM clusters were formed.The critical behavior analysis of this series of samples shows that the series of samples fit well with the mean field model.Through the Arrott curve and the recalibration curve,it is found that both the parent phase and the doped samples x=0.05,0.15 experienced the transition stage from the first-order phase transition to the second-order phase transition.The maximum magnetic entropy changes of the three samples with an external magnetic field of 5 T are 1.53,1.44,1.40 J·kg^(-1).K^(-1),respectively.

关 键 词：磁卡效应 磁制冷效率 二级相变 类Griffiths相 稀土 

分 类 号：O469[理学—凝聚态物理]