Die Seltenerdmetallpolyselenide Gd8Se15, Tb8Se15−x, Dy8Se15−x, Ho8Se15−x, Er8Se15−x und Y8Se15−x (0 < x ≤ 0.3) – Zunehmende Fehlordnung in ausgedünnten, planaren Selenschichten
Die Seltenerdmetallpolyselenide Gd8Se15, Tb8Se15−x, Dy8Se15−x, Ho8Se15−x, Er8Se15−x und Y8Se15−x (0 < x ≤ 0.3) – Zunehmende Fehlordnung in ausgedünnten, planaren Selenschichten
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Die Seltenerdmetalpolyselenide Gd8Se15, Tb8Se15−x, Dy8Se15−x, Ho8Se15−x, Er8Se15−x 和 Y8Se15−x (0 < x ≤ 0.3) – Zunehmende Fehlordnung in ausgedünnten, planaren Selenschichten
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
B. P. T. Fokwa
中科院分区：
文献类型：
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作者：
T. Doert;Enkhtsetseg Dashjav;B. P. T. Fokwa
稀土金属多硒化物Gd 8 Se 15，Tb 8 Se 15 −x，Dy 8 Se 15 −x，Ho 8 Se 15 −x，Er 8 Se 15 −x，和Y8 Se 15 −x -缺陷平面硒层中的无序增加
稀土金属多硒化物Gd 8 Se 15、Tb 8 Se 15 −x、Dy 8 Se 15 −x、Ho 8 Se 15 − x、Er 8 Se 15 −x和Y8 Se 15 −x（0 < x ≤ 0.3）的单晶已经通过化学输运反应（1120 K 970 K，14天，I2作为载体）从标称成分在LnSe 2和LnSe1.9之间的预退火粉末开始制备。同结构的标题化合物具有3 × 4 × 2的ZrSSi型超结构，空间群为Amm 2，晶格常数为a = 12.161（1）A，B = 16.212（2）A，c = 16.631（2）A（Gd_8 Se_（15）），a = 12.094（2）A，B = 16.123（2）A和c = 16.550（2）A（Tb 8 Se 15 −x），a = 12.036（2）A，B = 16.060（2）A和c = 16.475（2）A（Dy8Se 15 −x），a = 11.993（2）A，B = 15.999（2）A和c = 16.471（2）A（Ho 8 Se 15 −x），a = 11.908（2）A，B = 15.921（2）A和c = 16.428（2）A（Er 8 Se 15 −x），和a = 12.045（2）A，B = 16.072（3）A和c = 16.626（3）A（Y 8 Se 15 −x）。该结构由沿[001]沿着交替的褶皱[LnSe]双层和平面Se层组成。平面Se层包含二聚体、Se 2-和空位的无序排列。所有化合物都是半导体，含有三价稀土金属（Ln 3+）。
The Rare Earth Metal Polyselenides Gd8Se15, Tb8Se15−x, Dy8Se15−x, Ho8Se15−x, Er8Se15−x, and Y8Se15−x – Increasing Disorder in Defective Planar Selenium Layers
Single crystals of the rare earth metal polyselenides Gd8Se15, Tb8Se15−x, Dy8Se15−x, Ho8Se15−x, Er8Se15−x, and Y8Se15−x (0 < x ≤ 0.3) have been prepared by chemical transport reactions (1120 K 970 K, 14 days, I2 as carrier) starting from pre-annealed powders of nominal compositions between LnSe2 and LnSe1.9. The isostructural title compounds adopt a 3 × 4 × 2 superstructure of the ZrSSi type and can be described in space group Amm2 with lattice parameters of a = 12.161(1) A, b = 16.212(2) A and c = 16.631(2) A (Gd8Se15), a = 12.094(2) A, b = 16.123(2) A and c = 16.550(2) A (Tb8Se15−x), a = 12.036(2) A, b = 16.060(2) A and c = 16.475(2) A (Dy8Se15−x), a = 11.993(2) A, b = 15.999(2) A and c = 16.471(2) A (Ho8Se15−x), a = 11.908(2) A, b = 15.921(2) A and c = 16.428(2) A (Er8Se15−x), and a = 12.045(2) A, b = 16.072(3) A and c = 16.626(3) A (Y8Se15−x), respectively. The structure consists of puckered [LnSe] double slabs and planar Se layers alternating along [001]. The planar Se layers contain a disordered arrangement of dimers, Se2− and vacancies. All compounds are semiconducting and contain trivalent rare earth metals (Ln3+).