Dy掺杂钙钛矿锰氧化物Pr_(0.87)Ca_(0.13)MnO_(3)的磁性研究  

Magnetic properties of Dy-doped perovskite manganese oxide Pr_(0.87)Ca_(0.13)MnO_(3)

作　　者：郝志军 云慧琴 陈金欢 李成 赵建军[1] HAO Zhijun;YUN Huiqin;CHEN Jinhuan;LI Cheng;ZHAO Jianjun(Key Laboratory of Magnetism and Magnetic Materials in Universities of Inner Mongolia Autonomous Region,Baotou Teachers College,Baotou 014030,China)

机构地区：[1]包头师范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：《有色金属工程》2022年第5期14-21,共8页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(11164019,51562032,61565013);内蒙古自治区自然科学基金(2015MS0109);内蒙高校科学研究基金(NJZZ11166,NJZY12202);包头市科学技术局产学研合作项目(2014X1014-01,2015Z2011);内蒙古自治区研究生科研创新项目(S201710127(S01));高水平研究成果培育项目自然科学类青年项目(BSYKJ2021-ZQ08);内蒙古自治区研究生科研创新项目(S20210179Z)。

摘　　要：采用传统高温固相反应法制备了钙钛矿锰氧化物Pr_((0.87-x)D)y_(x)Ca_(0.13)MnO_(3)(x=0、0.05、0.1、0.15)系列多晶样品,研究Dy的掺杂量对母相Pr_(0.87)Ca_(0.13)MnO_(3)样品的结构、磁性以及磁热效应的影响。掺杂量为0、0.05和0.1的样品满足预成型团簇相的典型特征,而掺杂量为0.15的样品满足类Griffiths相的典型特征;当T<T_(N)时,该组样品铁磁性减弱,反铁磁性增强;在T_(C)<T<220 K的温度区间内,该组样品处于顺磁-铁磁共存态,对于Pr_(0.72)Dy_(0.15)Ca_(0.13)MnO_(3)样品,当T>T_(G)(330 K)时,此样品处于纯顺磁态。当外加磁场为7 T时,该组样品最大磁熵变的负值分别约为4.60770(x=0)、4.11222(x=0.05)、3.87818(x=0.1)、3.84890 J/(kg·K)(x=0.15),可见随着Dy元素的掺入,最大磁熵变的负值在减小,但却增加了半高宽温区的范围。由Arrott曲线和重标定曲线都可以说明,母相Pr_(0.87)Ca_(0.13)MnO_(3)样品和Pr_(0.82)Dy_(0.05)Ca_(0.13)MnO_(3)样品经历的都是二级相变,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)样品经历的都是一级相变。In this study,perovskite manganese oxide Pr_((0.87-x))Dy_(x)Ca_(0.13)MnO_(3)(x=0,0.05,0.1,0.15)series polycrystalline samples were prepared via high temperature solid reaction method.The effect of the doping amount of Dy on the crystal structure,magnetism and magnetothermal effects of the parent phase Pr_(0.87)Ca_(0.13)MnO_(3) were studied.Samples with doping amounts of 0,0.05 and 0.1 meet the typical characteristics of the preformed cluster phase,while the samples with doping amount of 0.15 meet the typical characteristics of the class Griffiths phase.When T<T_(N),the ferromagnetism of this group of samples is weakened,antiferromagnetism is enhanced.In the temperature range of T_(C)~220 K,the samples are in a paramagnetic and ferromagnetic coexistence state.For Pr_(0.72)Dy_(0.15)Ca_(0.13)MnO_(3),the sample is in a pure paramagnetic state at T>T_(G)(330 K).When the external magnetic field is 7 T,the maximum magnetic entropy of the samples was-ΔS M(0)≈4.60770,-ΔS M(0.05)≈4.11222,-ΔS M(0.1)≈3.87818,-ΔS M(0.15)≈3.84890 J/(kg·K),respectively,indicating that with the addition of Dy^(3+)ions,the maximum magnetic entropy decreases,but the temperature range of half high and wide is broaden.According to Arrott curve and recalculation curve,the parent phase sample of Pr_(0.87)Ca_(0.13)MnO_(3)and Pr_(0.87)Ca_(0.13)MnO_(3)sample undergo a second-order phase transition.In contrast,both Pr_(0.77)Dy_(0.1)Ca_(0.13)MnO_(3)sample and Pr_(0.72)Dy_(0.15)Ca_(0.13)MnO_(3)sample undergo first-order phase transition.

关 键 词：钙钛矿锰氧化物 磁熵变 高温区磁制冷 相变 

分 类 号：TB34[一般工业技术—材料科学与工程]