| 摘要: |
| 利用固相反应与球磨相结合的方法,制备了(Cu1-xMnx)CrO2 (0≤x≤6 at%) 和 Cu(Cr1-yMny)O2 (0≤y≤6 at%)两个系列的纳米粉体.结果表明,所有样品都具有3R-CuCrO2铜铁矿单相结构.晶格膨胀说明Mn离子已分别固溶到(Cu1-xMnx)CrO2的Cu亚晶格中和Cu(Cr1-yMny)O2的Cr亚晶格中,这在X射线光电子能谱的分析中得到了进一步的证实.B位Mn掺杂样品具有室温铁磁性,磁性源于Cr3+-Mn3+离子对间以空穴为媒介的双交换相互作用.CuMO2(M=Cr,Mn)铜铁矿纳米粉体的饱和磁化强度比文献值高出约一个数量级,并随着Mn含量的增大而逐渐减小,主要受到3个因素的共同影响:M-M离子对数目、M-M离子间距及空穴浓度. |
| 关键词: 稀磁半导体 纳米颗粒 微结构 磁性能 |
| DOI： |
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| Room-temperature ferromagnetism in Mn-doped CuCrO2 nanopowders |
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DENG Linyan, LIN Fangting, ZHANG Zhengjian
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College of Mathematics and Sciences,Shanghai Normal University
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| Abstract: |
| (Cu1-xMnx)CrO2 (0≤x≤6 at%) and Cu(Cr1-yMny)O2 (0≤y≤6 at%) nanopowders were prepared by combining solid-state reaction and ball milling.It is found that all the samples have a pure 3R-CuCrO2 delafossite structure.The lattice expansion supports the Mn entrance into the Cu and Cr sublattices,respectively,in (Cu1-xMnx)CrO2 and Cu(Cr1-yMny)O2,which is further proved by X-ray photoelectron spectroscopy to some degree.Room-temperature ferromagnetism is achieved in B-site Mn-doped samples,originating from the hole-mediated Cr3+-Mn3+ double-exchange interaction.The saturation magnetization of this CuMO2 delafossite (M=Cr,Mn) is about an order of magnitude higher than literature values,and gradually decreases with the Mn addition due to the combined influence of the number of the M-M pairs,the M-M distances and the hole density. |
| Key words: diluted magnetic semiconductors nanoparticles microstructure magnetic properties |
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