Willamson–Hall plot. X-ray photoelectron spectroscopy showed clear evidence for tetragonal coordinated high-spin Mn4+ ions occupying the lattice sites of Sn4+ in the SnO2 host. Electron energy loss spectroscopy further confirmed composition and oxidation states of Sn4+ and Mn4+ ions. Manganese doping increased the band gap of SnO2 from 4 eV to 4.40 eV with Mn4+ concentration. Variation in band gap energy
本文呈现应变和掺杂诱导的能带隙的变化的在Sn中的联合效果1- X的Mn X O(0≤ X ≤0.05)的纳米颗粒。另外,努力了解Mn掺杂对SnO 2的结构和光学性质的影响。X射线衍射分析显示为四边形结构,并且随着Mn 4+含量的增加,晶胞体积略有减少。Mn:SnO 2是球形颗粒,通过透射电子显微镜,Scherrer公式和Willamson-Hall图计算得出,其粒径范围为7.7至13.8 nm。X射线光电子能谱显示四方配位高自旋Mn 4+的明确证据离子占据SnO 2主体中Sn 4+的晶格位。电子能量损失谱进一步证实了Sn 4+和Mn 4+离子的组成和氧化态。锰掺杂使Mn 4+浓度使SnO 2的带隙从4 eV增加到4.40 eV 。带隙能量的变化归因于随Mn含量增加的晶格应变以及Mn 4+离子与SnO 2的导带/价带之间的电荷转移跃迁。当在250 nm激发时,在320、360和380 nm处
Crystal structure and phase relations for Mn3Sn2 and non-stoichiometric Mn2−xSn
作者:M. Stange、H. Fjellvåg、S. Furuseth、B.C. Hauback
DOI:10.1016/s0925-8388(97)00050-9
日期:1997.8
At 1073 K, the homogeneity range is 0.18≤x≤0.23, whereas at 873 K 0.28≤x≤0.34. The crystalstructure of Mn2−xSn is of the partly filled-up NiAs-type. The crystalstructure of the ordered Mn3Sn2 phase was solved on the basis of powder X-ray and neutron diffraction data. Mn3Sn2 is isostructural to Co3Sn2 and Ni3Sn2. Phase transformation and structural relationships are discussed.
摘要 有序Mn3Sn2在二元MnSn体系中表现为明显的低温相。在加热时,它在 813 K 左右分解成非常非化学计量的 Mn2-xSn 相和 MnSn2。Mn3Sn2 和 Mn2-xSn 的相关系是在合成过程中非常小心的样品的基础上描述的,以尽量减少由于锰蒸发和/或运输造成的不均匀性。Mn2-xSn 存在于 753 和 1157 K 之间。Mn2-xSn 的非化学计量与温度密切相关。在 1073 K 时,均匀性范围为 0.18≤x≤0.23,而在 873 K 时,均匀性范围为 0.28≤x≤0.34。Mn2-xSn 的晶体结构是部分填充的 NiAs 型。基于粉末 X 射线和中子衍射数据解析了有序 Mn3Sn2 相的晶体结构。Mn3Sn2 与 Co3Sn2 和 Ni3Sn2 同构。
Nanocomposites in the Sn–Mn–C system produced by mechanical alloying
作者:L Beaulieu、D Larcher、R.A Dunlap、J.R Dahn
DOI:10.1016/s0925-8388(99)00577-0
日期:2000.2
Intermetallic phases and mixtures of intermetallic phases in the Sn-Mn-C ternary system were prepared by mechanical alloying. Studies concentrated on Sn2Mn, SnMn1.77 and SnMn3C. Nanoscale two-phase mixtures of Sn2Mn-SnMn1.77 and Sn2Mn-SnMn3C were prepared and studied by electron microscopy, X-ray diffraction and Mossbauer spectroscopy. These results show that each particle is a mixture of nanoscopic grains of the coexisting phases. The grain sizes of the phases are shown to be in the 10 nm range. On the basis of the results in the Sn-Fe-C system the present investigation suggests that the materials prepared here may be suitable as anode materials for Li-ion cells. (C) 2000 Elsevier Science S.A. All rights reserved.
Resistivity Minima in<i>β</i>-Mn(Sn) Alloys
作者:Yutaka Nakai
DOI:10.1143/jpsj.67.4198
日期:1998.12.15
Electrical resistivities of beta-Mn(Sn) alloys were measured. Resistivity minima were observed above the freezing temperatures. Extra resistivity is found besides resistivities due to impurity and atomic vibration, and it is expressed by a log T term.
Evidence for atomic disorder in<i>B</i>8-structure Mn-Sn by mechanical milling
作者:G. F. Zhou、H. Bakker
DOI:10.1103/physrevb.48.7672
日期:——
Mechanical milling of ferrimagnetic B8-structure Mn1.5Sn results in a decrease of the magnetization at 4.2 K in a field of 21 T. This is in contrast to a number of other ferromagnetic B8-structure compounds, where the magnetization increases. The explanation is given in terms of a redistribution of transition-metal atoms over two different types of transition-metal sites. The Curie temperature (T(c)) of the compound also decreases. The unit-cell volume increases with milling time, which provides additional evidence for the particular type of atomic disorder. The material remains in its original crystal structure even after prolonged periods of ball milling.