应用化学 ›› 1994, Vol. 0 ›› Issue (3): 40-44.

• 研究论文 • 上一篇    下一篇

Pr2-xSrxNiO4±δ的合成、结构和电磁性质

李思温, 任玉芳, 王鸿燕   

  1. 中国科学院长春应用化学研究所稀土化学与物理开放实验室 长春 130022
  • 收稿日期:1993-06-26 修回日期:1994-01-14 出版日期:1994-06-10 发布日期:1994-06-10

Synthesis,Crystal Structure,Electrical and Magnetic Properties of Pr2-χSrχNiO4±δ

Li Siwen, Ren Yufang, Wang Hongyan   

  1. Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Scienes, Changchun 130022
  • Received:1993-06-26 Revised:1994-01-14 Published:1994-06-10 Online:1994-06-10

摘要: 用固相法合成了Pr2-χSrχNiO4±δ(0.0≤χ≤1.0)系列K2NiF4型化合物,研究了其结构,红外光谱,电磁性质。当0.0≤χ<0.1和χ=1.0时以正交晶系结晶;当0.1≤χ<1.0时以四方晶系结晶;Ni离子平均价态在+2至+3价之间。当χ值较小时,样品中含有过量的氧。NiOδ八面体中Ni3+的Jahn-Teller畸变引起c/a值在χ=0.5处出现极大,在77~250K之间,样品磁性质符合居里-外斯定律,并表现出反铁磁相互作用。电学性质的变化可以理解为Ni3+离子电子组态由t6dZ12变至t6dZ12-y2的结果

关键词: 镨锶镍复合氧化物, 晶体结构, 电学性质, 磁学性质

Abstract: A series of solid soItition Pr2-χSrχNiO4(0.00≤χ≤1. 00) were synthesized with the nickel valence being +2 to +3.The mixed oxides crystallized in orthorhombic(0.00≤χ<0.10 and x=1.00) or tetragonal system(0.10≤χ<1.00). The crystal parameter ratio c/a shows a maximum at χ = 0.5 caused by Jahn-Teller distortion in octahedral site of the low-spin Ni3+ ions. The magnetic susceptibilities of the mixed oxides follow the Curie-Weiss rule at temperatures 77~250K. An antiferomagne exchange interaction was observed in all the samples.The change of electrical properties in the system of χ>0.5 is attributed to the change of electronic configuration of Ni3+ from t6dZ12 to t6dZ12-y2.

Key words: praseodium-strontium-nickel mixed oxide, crystal structure, electrical property, magnetic property