کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1482356 991563 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
XAFS investigations of nitrided NbN–SiO2 sol–gel derived films
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
XAFS investigations of nitrided NbN–SiO2 sol–gel derived films
چکیده انگلیسی

This work presents the results of the structural analysis of xNbN–(100-x)SiO2 (x = 100, 80, 60 mol%) thin films by X-ray absorption spectroscopy (XAS). To prepare the films, thermal nitridation of sol–gel derived coatings have been performed. The resulting films have a granular structure with NbN grains distributed in the SiO2 matrix. The size of the grains depends on the NbN/SiO2 molar ratio. A detailed X-ray absorption fine structure (XAFS) data analysis shows that in all the samples both nitrogen and oxygen atoms are present as nearest neighbours of Nb. The intra-granular phase is an ordered NbN phase, whereas the shells around the grains are formed mainly by an oxide phase and, possibly, by other niobium nitride phases (probably with low nitrogen content). Two possible origins of the inter-granular oxide phase were considered: incomplete nitridation of Nb2O5 and addition of SiO2. Both of them are connected with the sample preparation method. The obtained XAS results allowed us to correlate the thickness and stoichiometry of the films under study with the electronic structure of the Nb ions and with the local geometric structure in their environment.


► This work presents the structural analysis of NbN–SiO2 sol–gel derived thin films.
► We focused on X-ray Absorption Fine Structure analysis of the Nb local environment.
► Data analysis shows that the intra-granular phase is an ordered NbN phase.
► The shells around the grains are formed mainly by an oxide phase.
► Granular structure is strongly related to the film thickness and stoichiometry.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 358, Issue 5, 1 March 2012, Pages 969–974
نویسندگان
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