کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5447983 1511766 2017 21 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thermally induced phase transformations of lepidocrocite-like ferrititanate nanosheets synthesized from a low cost precursor by hydrothermal method
ترجمه فارسی عنوان
تغییرات فازی ناشی از حرارتی از نانوذرات فرتیتیانات مانند لیپیدوکروسیتی مانند سنتز شده از پیش تعیین شده با هیدروترمال
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
چکیده انگلیسی
Thermal stability and phase transformation paths of Lepidocrocite-like layered titanates (LTs-NS) are not well established. This is especially true for the ferrititanate nanosheets, recently synthesized from mineral sands. High-temperature phase transformation paths of three types of lepidocrocite-like layered ferrititanate nanosheets were examined by in situ HT-XRPD and TG analyses. We analyzed sodium-rich (NaLTs-NS), protonated (pLTs-NS), and a nanohybrid (pLTs-o-2C18-NS) nanosheets, the last one composed from the individual ferrititanate host layers and dimethyldioctadecylammonium cations (2C18+). We investigated how the presence of Na+, H+ and 2C18+ influences the thermal behavior of LTs nanosheets. The three materials show different thermal evolution paths. Na-LTs-NS exhibit the highest thermal stability, where the layered structure is preserved to at least 600 °C. Na-LTs-NS transform to freudenbergite (Na2(Ti,Fe)8O16) at 700 °C. Rutile and pseudobrookite form at higher temperatures in Na-rich ferrititanate system and coexist with freudenbergite. Thermal stability of protonated nanosheets is much lower since the layered structure is destroyed under 500 °C. High temperature phases pseudobrookite (Fe2TiO5) and rutile (TiO2) crystallize at ∼700 °C which is in accordance with the stability field for the Fe2O3-TiO2 binary phase diagram rich in TiO2. In the case of pLTs-o-2C18-NS rutile and hematite form at 650 °C.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Chemistry and Physics - Volume 197, 15 August 2017, Pages 138-144
نویسندگان
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