YPdSn and YPd<sub>2sub>Sn: Structure, <sup>89sup>Y solid state NMR and <sup>119sup>Sn M枚ssbauer spectroscopy
- 作者：Christoph Hö ; ting<sup>asup> ; Hellmut Eckert<sup>bsup> ; Thorsten Langer<sup>asup> ; Inga Schellenberg<sup>asup> ; Rainer Pö ; ttgen<sup>asup><sup> ; sup><sup>pottgen@uni-muenster.desup>
- 关键词：Stannides ; Crystal chemistry ; 89Y solid state NMR ; 119Sn Mö ; ssbauer spectroscopy
- 刊名：Journal of Solid State Chemistry
- 出版年：2012
- 期刊代码：130_00224596
- 类别：ch
- 出版时间：June, 2012
- 卷：190
- 期：Complete
- 页码：216-220
- 文件大小：391 K
摘要
The stannides YPdSn and YPd<sub>2sub>Sn were synthesized by high-frequency melting of the elements in sealed tantalum tubes. Both structures were refined on the basis of single crystal X-ray diffractometer data: TiNiSi type, Pnma, a=715.4(1), b=458.8(1), c=789.1(1) pm, wR2=0.0461, 510 F<sup>2sup> values, 20 variables for YPdSn and MnCu<sub>2sub>Al type, Fm3炉m, a=671.44(8), wR2=0.0740, 55 F<sup>2sup> values, 5 parameters for YPd<sub>2sub>Sn. The yttrium atoms in the new stannide YPdSn are coordinated by two tilted Pd<sub>3sub>Sn<sub>3sub> hexagons (ordered AlB<sub>2sub> superstructure). In the Heusler phase YPd<sub>2sub>Sn each yttrium atom has octahedral tin coordination and additionally eight palladium neighbors. The cubic site symmetry of yttrium is reflected in the <sup>119sup>Sn M枚ssbauer spectrum which shows no quadrupole splitting. In contrast, YPdSn shows a single signal at 未=1.82(1) mm/s subjected to quadrupole splitting of 螖E<sub>Qsub>=0.93(1) mm/s. Both compounds have been characterized by high-resolution <sup>89sup>Y solid state NMR spectroscopy, which indicates the presence of strong Knight shifts. The spectrum of YPd<sub>2sub>Sn is characterized by an unusually large linewidth, suggesting the presence of a Knight shift distribution reflecting local disordering effects. The range of <sup>89sup>Y Knight shifts of several binary and ternary intermetallic yttrium compounds is briefly discussed.