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纳米复相锌铁氧体的隧道结构与相变动力学分析

张栋杰1; 都有为2   

  1. 1. 南京师范大学材料科学重点实验室, 南京 210097; 2. 南京大学固体微结构国家实验室 南京 210093
  • 收稿日期:2003-01-16 修回日期:2003-03-27 出版日期:2004-01-20 网络出版日期:2004-01-20

Tunneling Structure and Phase-Transformation Dynamics of Two-PhaseFerrite of ZnFe2O4/Fe2O3

ZHANG Dong-Jie1; DU You-Wei2   

  1. 1. Laboratory of Materials Science; Nanjing Normal University; Nanjing 210097; China; 2. National Laboratory of Solid State Microstructure; Nanjing University; Nanjing 210093; China
  • Received:2003-01-16 Revised:2003-03-27 Published:2004-01-20 Online:2004-01-20

摘要: 采用sol-gel方法制备了ZnFe2O4/Fe2O3纳米复相铁氧体.利用X射线衍射,高分辨电镜(HREM)对样品的结构进行了分析.结果表明,复相锌铁氧体是形成隧道结构的必要条件;伏安曲线和磁电阻效应等从性能上说明复相锌铁氧体具有隧道磁电阻的特性;HREM直接观测到复相锌铁氧体形成隧道结构,其中绝缘层α-Fe2O3位于晶界处,从相变动力学分析中,也证实了α-Fe2O3是由ZnFe2O4晶界或表面控制的析晶,位于晶界处.

关键词: 铁氧体, 隧道结构, 动力学, ZnFe2O4

Abstract: The nanostructure ferrites of two-phase ZnFe2O4/Fe2O3 were prepared by the sol-gel method.
The structure was analyzed by X-ray diffraction (XRD) and high-resolution electron microscope (HREM). The
results indicate that two-phase ferrite is the necessary condition to form tunneling structure. Non-Ohmic character
of I-V curve and magnetoresistance effect of two-phase ferrite also show tunneling character. The tunneling
structure was directly observed by HREM in two-phase ferrite that insulating layer of α-Fe2O3
located in interface between ferrets. Approved deeply by phase-transformation dynamics, crystallization of α-Fe2O3
is controlled by the interface or surface of ZnFe2O4 crystallite.

Key words: ferrite, tunneling structure, dynamics, ZnFe2O4

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