Dy掺杂Pr_(0.87)Ca_(0.13)MnO_(3)体系的磁热效应和临界行为的研究  

Study on the Magnetothermal Effect and Critical Behavior of Dy Doped Pr_(0.87)Ca_(0.13)MnO_(3)System

作　　者：郝志军 赵建军[1,3] 云慧琴 赵晶 邢婷 马怀瑾 王雁冰 HAO Zhijun;ZHAO Jin-jun;YUN Hui-qin;ZHAO Jing;XIN Ting;MA Huai-jin;WANG Yan-bing(School of Physical Science and Technology,Baotou Teacher's College,Baotou 014030,China;Inner Mongolia Zhonghuan Crystal Materials Co.,Ltd.,Hohhot 010020,China;Key Laboratory of Magnetism and Magnetic Materials,Universities of Inner Mongolia Autonomous Region,Baotou 014030,China)

机构地区：[1]包头师范学院物理科学与技术学院,内蒙古包头014030 [2]内蒙古中环晶体材料有限公司,内蒙古呼和浩特010020 [3]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：《稀土》2024年第3期38-48,I0004,共12页Chinese Rare Earths

基　　金：国家自然科学基金项目(11164019,51562032,61565013);内蒙古自治区研究生科研创新项目(S20210179Z);高水平研究成果培育项目自然科学类青年项目(BSYKJ2021-ZQ08);专业认证下的近代物理实验教学改革与探索(BSJG22Y14)。

摘　　要：钙钛矿结构金属氧化物展现出了丰富的磁性,A位掺杂对磁性能的调控也是钙钛矿结构金属氧化物研究的重要方向。采用高温固相反应法制备了Pr_((0.87-x))Dy_(x)Ca_(0.13)MnO_(3)(x=0,0.05,0.1,0.15)系列多晶样品,重点研究了Dy^(3+)掺杂量对母相Pr_(0.87)Ca_(0.13)MnO_(3)样品晶体结构、磁热效应和临界行为的影响。Pr_((0.87-x))Dy_(x)Ca_(0.13)MnO_(3)(x=0,0.05,0.1,0.15)系列样品具有良好的结晶度,纯度很高,空间点群为正交晶系Pnma,属于立方结构;Pr_(0.82)Dy_(0.05)Ca_(0.13)MnO_(3)样品可能是一种优良的磁制冷材料,其制冷能力(RC值)为114.73 J·kg^(-1)(0~3 T)、222.92 J·kg^(-1)(0~5 T)、351.88 J·kg^(-1)(0~7 T),相对制冷能力(RCP值)为468.79308 J·kg^(-1)(0~7 T);绝热温度(ΔT_(ad))分别为4.21 K、4.30 K、4.51 K、4.96 K。母相Pr_(0.87)Ca_(0.13)MnO_(3)样品和Pr_(0.82)Dy_(0.05)Ca_(0.13)MnO_(3)样品经历的是二级相变,Pr_(0.77)Dy_(0.1)Ca_(0.13)MnO_(3)样品和Pr_(0.72)Dy_(0.15)Ca_(0.13)MnO_(3)样品经历的是一级相变;利用不同的模型对样品进行拟合和Kouvel-Fisher(K-F)方法来计算临界指数,最终得出该组样品的相变临界行为为平均场模型;该组样品中均存在磁晶各向异性和反铁磁的成分。Perovskite structure metal oxides show rich magnetic properties,and the regulation of magnetic properties by A-site doping is also an important direction in the study of perovskite structure metal oxides.In this paper,Pr_((0.87-x))Dy_(x)Ca_(0.13)MnO_(3)(x=0,0.05,0.1,0.15)series polycrystalline samples were produced by high temperature solid phase reaction method.The influence of doping amount of Dy^(3+)on crystal structure,magnetothermal effect and critical behavior of parent Pr_(0.87)Ca_(0.13)MnO_(3) were studied.The Pr_((0.87-x))Dy_(x)Ca_(0.13)MnO_(3)(x=0,0.05,0.1,0.15)series samples have good crystallinity and high purity,and the spatial point group is orthorhombic system Pnma,which belongs to cubic structure.The Refrigeration capacities of Pr_(0.82)Dy_(0.05)Ca_(0.13)MnO_(3) are 114.73 J·kg^(-1)(0~3 T),222.92 J·kg^(-1)(0~5 T)and 351.88 J·kg^(-1)(0~7 T),and Pr_(0.82)Dy_(0.05)Ca_(0.13)MnO_(3) may be an excellent magnetic refrigeration material.The Relative refrigeration capacity was 468.79308 J·kg^(-1)(0^7 T),and the adiabatic temperatures(ΔT_(ad))were 4.21 K,4.30 K,4.51 K and 4.96 K,respectively.The parent phase Pr_(0.87)Ca_(0.13)MnO_(3) and Pr_(0.82)Dy_(0.05)Ca_(0.13)MnO_(3) samples undergo second-order phase transition while they undergo first-order phase transition.Through fitting Arrott curves of samples by using different models and calculating the critical index with Kouvel-Fisher(K-F)method,it is concluded that the critical behavior of this group of samples is the mean field model.There are magnetic crystal anisotropy and antiferromagnetic components in the samples.

关 键 词：钙钛矿锰氧化物 高温固相反应法 磁热效应 临界行为 稀土 

分 类 号：O614.33[理学—无机化学]