Role of oxygen vacancies in tuning magnetic properties of Co-doped SnO2 insulating films
Role of oxygen vacancies in tuning magnetic properties of Co-doped SnO2 insulating films
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DOI：
10.1063/1.2747591
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发表时间：
2007-06
影响因子：
3.2
通讯作者：
Xi-Jing Liu;Yilin Sun;R. Yu
中科院分区：
文献类型：
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作者：
Xi-Jing Liu;Yilin Sun;R. Yu
制备了一系列在不同氧分压下沉积并在不同气氛下退火的薄膜，研究了氧空位在Co掺杂SnO2薄膜磁性能调节中的作用。SnO2中的Co以2+态存在，取代Sn4+位。在所有的薄膜中观察到本征室温铁磁性，这不是载流子介导的，但与介电行为共存。真空退火使薄膜中氧空位的增加和扩散而不是提高薄膜的结晶度，从而使薄膜的磁矩达到最大值2.37 μB scinCo，而空气退火或提高氧分压后，磁矩显著降低。氧空位浓度和分布的变化可通过XPS谱中Co 2 p3 scin2峰的相对位移间接反映出来。Co掺杂的SnO2薄膜的禁带宽度比纯SnO2薄膜的禁带宽度大，说明Co掺杂对薄膜的禁带宽度有影响。
A series of films deposited under different oxygen partial pressures and annealed under different atmospheres were prepared to investigate the role of oxygen vacancies in tuning magnetic properties of Co-doped SnO2 films. The inclusive Co in SnO2 is in the 2+ state and substitutes for the Sn4+ site. Intrinsic room temperature ferromagnetism is observed in all films, which is not carrier mediated, but coexists with the dielectric behavior. A maximum magnetic moment of 2.37 μB∕Co is achieved by vacuum annealing due to the increase and diffusion of oxygen vacancies rather than the improvement of crystallinity of the film, and the magnetic moment decreases considerably after air annealing or increasing the oxygen partial pressure during deposition. The changes of oxygen vacancy concentration and distribution are indirectly demonstrated by the relative shifts of Co 2p3∕2 peaks in XPS spectra. The band gap of Co-doped SnO2 film is larger than that of pure SnO2 film, suggesting the influence of inclusive Co on t...