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arXiv 0903.1691cond-mat.str-el
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Zn0.95 Mn 0.05 O室温铁磁性的再现及其认识

Reproducibility of room temperature ferromagnetism in Zn0.95Mn0.05O and its understanding

R. N. Bhowmik, Asok Poddar, A. Saravanan

摘要:

通过在抗磁性ZnO中掺杂磁性Mn原子,再现了室温铁磁性。机械球磨Zn 0.95 Mn 0.05 O样品的铁磁有序性可扩展到640 K。块体和纳米晶样品稳定在六方晶体结构中,空间群为p63 mc。采用Williamson-Hall图从XRD谱估计样品的晶粒尺寸和晶格应变,显示出随球磨时间的显著变化。从SEM照片和室温下的EDX光谱观察到表面结构(形貌、晶粒和元素的分布)相当良好。块状、球磨和合金化样品中的铁磁有序主要是由于Mn(2+)离子扩散到ZnO的晶格位置。根据已有的理论预测和实验工作,讨论了磁矩和铁磁有序温度随晶粒尺寸减小而提高的现象。机械球磨诱导的无序的作用,增强室温铁磁性的Zn 0.95 Mn 0.05 O(稀磁半导体)也被突出。

英文摘要:

The present work reproduces the room temperature ferromagnetism by doping magnetic Mn atoms in diamagnetic ZnO. The ferromagnetic ordering is extended up to 640 K in mechanical milled Zn0.95Mn0.05O samples. The bulk and nanocrystalline samples are stabilized in hexagonal crystal structure with space group p63mc. The grain size and lattice strain of the samples, estimated from XRD spectrum using Williamson-Hall plot, showed a significant variation with milling time. Surface structure (morphology, distribution of grains and elements) is observed to be reasonably good from SEM picture and EDX spectrum at room temperature. The ferromagnetic ordering in bulk, milled and alloyed samples is primarily due to the diffusion of Mn(2+) ions into the lattice sites of ZnO. The enhancement of magnetic moment and ferromagnetic ordering temperature with reducing the grain size is discussed in terms of the existing theoretical predictions and experimental works. The role of mechanical milling induced disorder for the enhancement of room temperature ferromagnetism in Zn0.95Mn0.05O (dilute magnetic semiconductor) is also highlighted.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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