Mn和Fe掺杂SnO2的水热合成与磁结构研究

采用水热法合成了Sn1-x-yMnxFeyO2(0≤x≤0.10, 0≤y≤0.10)稀磁半导体. 通过XRD, Raman, TEM, SQUID和Mössbeaur等技术对化合物进行了结构和性能的表征. 结果表明, XRD中没有出现第二相的沉积, Raman光谱中出现了Mn位于SnO2晶格中的局域模式. 磁性测试结果表明, 当x=0.10, y=0时, 样品在低温下具有较强的磁化强度, 但室温下其磁化强度急剧降低. 而y=0.10, x=0时, 样品的磁化强度和矫顽力都比较小, 但随温度的改变变化不大, Mössbeaur谱测试结果表明, 其中的Fe一部分是铁磁耦合的, 拟合得到超精细场和同质异能移等参数表明, 铁磁性来源于Fe替代SnO2本征性能. Mn和Fe共同掺杂的样品的磁化强度随x的减少和y的增加而减少, 矫顽力却相对于单一元素掺杂的样品大大增加.

Hydrothermal Synthesis of Fe and Mn Doped SnO2 and Its Magnetic Structures

The dilute magnetic semiconductor of Sn1-x-yMnxFeyO2(0≤x≤0.10, 0≤y≤0.10) were synthesized with the hydrothermal method using SnCl4, Mn(CH3COO)2·4H2O and FeCl3·6H2O as the raw materials. The structure, morphologies and magnetic properties of the sample were characterized via X-ray powder diffractometer(XRD), transmission electron microscopy(TEM), Raman spectrum and superconducting and quantum interference device(SQUIT), and Mssbeaur spectrum. No secondary phase was found in the XRD spectrum. The morphology of the samples is affected by the kind or the mount of transition metal. The local vibrating model of Mn Positioned SnO2 sites was found in Raman spectrum. The measured magnetic results indicate that when x=0.10, y=0, the sample exhibits strong magnetization in low-temperature(5 K), but the magnetization decrease rapidly at room temperature; In contrast, when x=0, y=0.1, the sample's magnetization and coercivity are both small, but being temperature independent. Mössbeaur spectra indicates that part of the Fe is ferromagnetic coupled, and the simulating results indicate that the ferromagnetic character is intrinsic. The magnetization of the Mn and Fe codoping system decrease with the decrease of x and increase of y, However, the coercivity is comparatively enhanced in the codoping system.