کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1333410 979077 2007 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The effect of B2O3 addition on the crystallization of amorphous TiO2–ZrO2 mixed oxide
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
The effect of B2O3 addition on the crystallization of amorphous TiO2–ZrO2 mixed oxide
چکیده انگلیسی

The effect of B2O3 addition on the crystallization of amorphous TiO2–ZrO2 mixed oxide was investigated by X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG/DTA). TiO2–ZrO2 mixed oxide was prepared by co-precipitation method with aqueous ammonia as the precipitation reagent. Boric acid was used as a source of boria, and boria contents varied from 2 to 20 wt%. The results indicate that the addition of small amount of boria (<8 wt%) hinders the crystallization of amorphous TiO2–ZrO2 into a crystalline ZrTiO4 compound, while a larger amount of boria (⩾8 wt%) promotes the crystallization process. FT-IR spectroscopy and 11B MAS NMR results show that tetrahedral borate species predominate at low boria loading, and trigonal borate species increase with increasing boria loading. Thus it is concluded that highly dispersed tetrahedral BO4 units delay, while a build-up of trigonal BO3 promote, the crystallization of amorphous TiO2–ZrO2 to form ZrTiO4 crystals.

The addition of small amount of boria (<8 wt%) hinders the crystallization of amorphous TiO2–ZrO2 into a crystalline ZrTiO4 compound, while the larger amount of boria (⩾8 wt%) promotes the crystallization process.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Solid State Chemistry - Volume 180, Issue 2, February 2007, Pages 484–488
نویسندگان
, ,