ZnxFe3-xO4粉末的高温固相法制备及其磁学性质和输运性质

High-temperature solid state synthesis and characterization in magnetic and transporting properties of ZnxFe3-xO4 powder

  • 摘要: 分别在空气和N2中高温烧结得到了不同掺杂浓度的Fe3O4:Zn粉末.X射线衍射(XRD)结果表明,空气中烧结使得样品过氧化,生成大量的α-Fe2O3相,而N2环境下烧结可以获得较纯的ZnxFe3-xO4相.Zn2+在反尖晶石结构中A位的替位掺杂,影响到B位Fe阳离子的价态分布,电子输运依然保持了电子变程跳跃的传导机制.磁性测量结果显示低浓度的Zn2+掺杂对Fe阳离子之间的超交换耦合作用产生影响,也使负的磁致电阻的数值有所改善.

     

    Abstract: Zn-doped magnetite Fe3O4 samples were prepared at different doped concentrations and annealed at high temperature in ambient air and N2 respectively. X-ray diffraction (XRD) results showed that samples annealed in air were oxidized and the consequent products were partially in α-Fe2O3 form. While for the samples annealed in N2, ZnxFe3-xO4 products of high purity were obtained. The doping of Zn2+ on the tetrahedral sites (A sites) changed the valence distribution of Fe2+ ions on the octahedral sites (B sites). The electron transporting mechanism remained to be variable range hopping (VRH) conduction. Measurement results of magnetic properties indicated that the super exchange coupling interaction between Fe2+ ions was affected by the low doping concentration of Zn2+ ions in the crystal, and the negative magnetoresistivity of ZnxFe3-xO4 was improved as well.

     

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