کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1333626 | 979086 | 2006 | 9 صفحه PDF | دانلود رایگان |
A temperature dependent electron diffraction study has been carried out on UAsSe to search for evidence of As–As dimerization at low temperature. A highly structured characteristic diffuse intensity distribution, closely related to that recently reported for ThAsSe, has been observed at low temperature and interpreted in terms of a gradual charge density wave type phase transition upon lowering of temperature involving disordered As–As dimerization within (001) planes. Plausible models of the proposed As–As dimerization have been obtained using a group theoretical approach. Electronic band structure calculations of ThAsSe and UAsSe have been used to search for potential Fermi surface nesting wave-vectors. The results are in good agreement with the experimentally observed diffuse intensity distributions in both cases.
A typical 〈001〉 zone axis EDP of UAsSe taken at ∼80–90 K. In addition to the strong Bragg reflections of the underlying P4/nmm average structure, note the presence of a highly structured characteristic diffuse intensity distribution arising from disordered As–As dimerization.Figure optionsDownload as PowerPoint slide
Journal: Journal of Solid State Chemistry - Volume 179, Issue 7, July 2006, Pages 2190–2198