Sr2YRu1-xZnxO6结构、磁性及电输运特性

采用固相烧结工艺制备了Sr2YRu1-xZnxO6(x=0,0.1,0.2)陶瓷样品,采用多晶X射线和扫描电子显微镜技术对样品的物相成分、晶体结构和晶体表面形貌进行了表征与分析,将Sr2YRu1-xZnxO6(x=0,0.1,0.2)样品X射线衍射谱与理论模拟多晶样品X射线标准谱比较显示样品单相已经形成.X射线的实验结果表明:样品均形成了在a-b方向上具有双倍周期的钙钛矿结构,属于立方晶系,晶体空间群为Fm3m(No 225).Sr2YRuO6原胞为立方结构(a=0.816 4 nm),Y离子和Ru离子分别有序占据4a(0,0,0)和4b(1/2,1/2,1/2)原子等效位置.并且发现样品X射线衍射谱中的(111)衍射峰为B位Y离子和Ru离子有序占据时的特征峰.实验显示Zn离子取代Ru离子对晶胞参数影响很小.振动样品磁强计(VSM)测量了在常温下样品Sr2YRu1-xZnxO6(x=0,0.1,0.2)磁化强度与磁场强度的关系,样品在常温下显示顺磁性.计算得到Sr2YRuO6中Ru离子的有效磁矩为2.417 μB.用标准的四端子测量方法测量了样品的电阻随温度的关系,样品电阻随掺杂量的增加而降低,并且实现了由反铁磁绝缘体向半导体转变.

STRUCTURE、 TRANSPORT PROPERTY AND MAGNETISM OF Sr2 YRu1-x ZnxO6

Zn-doping Sr2YRu1-xZnxO6 (x=0,0.1,0.2) system with peroviskite structure have been synthesized by solid-state reaction method. The structure and the surface morphology of the sample are investigated by X-ray diffraction and scanning electron microscope. Sr2YRuO6 is found to be of a cubic lattice cell with a=b=c=0.816 4 nm,where Y and Ru ions occupy the B site of double perovskite cell oderly. Its single-phase characteristic can be maintained up to Zn-doping content x=0.2. The electrical resistivity of the sample has been measured by traditional four-probe technique. Sr2YRuO6 is found to exhibit the typical electrical transport behavior of an antiferromagnetic insulator as reported. As a whole, a transition from a paramagnetic insulator to a paramagnetic semiconductor caused by Zn doping was observed in Sr2YRu1-xZnxO6 (x=0,0.1,0.2) double perovskite system.