物理学报Issue(4)：047503-1-047503-10,10.DOI:10.7498/aps.63.047503
氧化镁纳米多晶的微结构和磁性
Magnetism of MgO nanoparticles
摘要
Abstract
MgO polycrystal is found to be weakly magnetic experimentally, although its single crystal is non magnetic. In this work, the magnetic properties of surfaces of crystal and nano-particles of MgO are studied by the first-principles density functional theory. The obtained results show that there are the oxygen-rich regions in all the magnetic surfaces discussed in this work, especially in the (111) surface with pure oxygen layer and the (114) surface with pure oxygen chains. Other surfaces with high Miller indices generally have the oxygen-rich regions. For MgO nano-particles, the facets with high Miller indices and the edges and vertexes formed by different orientation surfaces are oxygen-rich possibly and have strong magnetism. The itinerant magnetism is indentified for the magnetism on the surfaces of MgO crystal and the surfaces of MgO nano-particles. That the special MgO Σ7[111] grain boundary is not magnetic means that the magnetism of MgO grain boundary is weak if the chemical composition in grain-boundary region is slightly different from that in the crystal. It can be inferred that the magnetism of MgO polycrystal is mainly contributed by the polycrystal surface, the micro-pores, micro-voids and micro-cracks.关键词
氧化镁/纳米颗粒/表面磁性/第一性原理电子结构计算Key words
magnesium oxide/nanopaticles/surface magnetism/first-principles calculation of electronic structure引用本文复制引用
范巍,曾雉..氧化镁纳米多晶的微结构和磁性[J].物理学报,2014,(4):047503-1-047503-10,10.基金项目
国家重点基础研究发展计划(批准号:2012CB933702)、国家自然科学基金(批准号:11174284)和国家自然科学基金联合基金重点项目(批准号：U1230202)资助的课题.* Project supported by the National Basic Research Program of China (Grant No.2012CB933702), the National Natural Science Foundation of China (Grant No.11174284), and the Key Program of Joint Funds of the National Natural Science Foundation of China (Grant No. U1230202) （批准号:2012CB933702）
