...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Zeitschrift fur Anorganische und Allgemeine Chemie >Synthesis, structure, and properties of the tantalum-rich silicide chalcogenides Ta(15)Si(2)Q(x)Te(10-x) (Q = S, Se) [German]
【24h】

Synthesis, structure, and properties of the tantalum-rich silicide chalcogenides Ta(15)Si(2)Q(x)Te(10-x) (Q = S, Se) [German]

机译：富钽硅化物硫族化物Ta（15）Si（2）Q（x）Te（10-x）（Q = S，Se）的合成，结构和性质[Q]

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The quaternary tantalum silicide chalcogenides Ta(15)Si(2)Q(x)Te(10-x) (Q = S, Se) are accessible from proper, compacted mixtures of the respective dichalcogenides, silicon and elemental tantalum at 1770 K in sealed molybdenum tubes. The structures were determined from the strongest X-ray intensities of fibrous crystals with cross sections of about 3 mum and confirmed by fitting the profile of single phase X-ray diffractograms. The phases Ta15Si2S3.5Te6.5 and Ta15Si2Se3.5Te6.5 crystallize in the monoclinic space group C2/m with two formula units per unit cell, a = 2393.7(1) pm, b = 350.08(2) pm, c = 1601.2(1) pm, beta = 124.700(4)degrees, and a = 2461.3(2) pm, b = 351.70(2) pm, c = 1601.7(1) pm, beta = 124.363(5)degrees, respectively. Tri-capped trigonal prismatic Ta9Si clusters stabilized by encapsulated Si atoms can be seen as the characteristic unit of the structure. The clusters are fused into twin columns which are connected by additional Ta atoms, thus forming corrugated layers. The remaining valences at the surfaces of the layered Ta-Si substructure are saturated by those of chalcogen atoms which are coordinated only from one side by three, four or five Ta atoms. Few bridging covalent Ta-S-Ta and Ta-Se-Ta bonds and, otherwise, dispersive interactions between the Q atoms hold these nearly one nanometer wide slabs together. The phases are moderate metallic conductors. There is no evidence for any electronic instability within 10-310 K in spite of the high anisotropy of the structures. [References: 33]
机译：季铵化硅化硫属元素Ta（15）Si（2）Q（x）Te（10-x）（Q = S，Se）可通过适当的压实混合物分别从二硫化钨，硅和元素钽中以1770 K密封钼管。由具有约3μm横截面的纤维状晶体的最强X射线强度确定结构，并通过拟合单相X射线衍射图的轮廓确认。 Ta15Si2S3.5Te6.5和Ta15Si2Se3.5Te6.5相在单斜空间群C2 / m中结晶，每个晶胞具有两个公式单位，a = 2393.7（1）pm，b = 350.08（2）pm，c = 1601.2（ 1）pm，beta = 124.700（4）度，a = 2461.3（2）pm，b = 351.70（2）pm，c = 1601.7（1）pm，beta = 124.363（5）度。由包封的硅原子稳定的三封三角形棱柱形Ta9Si簇可以看作是结构的特征单元。团簇融合成双列，通过附加的Ta原子连接，从而形成波纹层。层状Ta-Si子结构的表面上的剩余化合价被硫族原子的饱和化合价所饱和，硫族原子仅从一侧由三个，四个或五个Ta原子配位。几乎没有架桥的共价Ta-S-Ta和Ta-Se-Ta键，否则，Q原子之间的色散相互作用将这些近1纳米宽的平板结合在一起。相是中等金属导体。尽管结构具有很高的各向异性，但没有证据表明在10-310 K范围内存在任何电子不稳定性。 [参考：33]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号