Izvorni znanstveni članak
X-ray diffraction study of thermal properties of titanium dioxide
Stanko Popović
; Physics Department, Faculty of Science, University of Zagreb, Bijenička cesta 32, HR-10002 Zagreb, POB 331, Croatia
Željko Skoko
; Physics Department, Faculty of Science, University of Zagreb, Bijenička cesta 32, HR-10002 Zagreb, POB 331, Croatia
Andreja Gajović
; Ruđer Bošković Institute, POB 180, 10002 Zagreb, Croatia
Krešimir Furić
; Ruđer Bošković Institute, POB 180, 10002 Zagreb, Croatia
Svetozar Musić
; Ruđer Bošković Institute, POB 180, 10002 Zagreb, Croatia
Sažetak
Temperature dependence of microstructure of titanium dioxide, TiO2, and the phase transition of anatase (A) to rutile (R) were studied by in situ X-ray powder diffraction. The as-synthesized TiO2 p.a. showed a gradual transition A→R during the temperature increase from ≈ 1200 K to ≈ 1570 K and during the temperature decrease to ≈ 600 K. High-energy ball milling at room temperature induced a partial transition A→R. The transition continued during the temperature increase to ≈ 1370 K and during the temperature decrease, and is accompanied by sharpening of diffraction lines. Anisotropy of thermal expansion was noticed for both A and R. In the transition A→R, the nuclei of R are formed either throughout the A crystallites (in the case of as-synthesized TiO2 p.a.) or mainly in the interior of the A crystallites (in the case of the milled TiO2 p.a.). These nuclei grow in number and size with a prolonged time of thermal agitation.
Ključne riječi
titanium dioxide; rutile; anatase; phase transition; thermal expansion; X-ray powder diffraction
Hrčak ID:
301813
URI
Datum izdavanja:
1.3.2005.
Posjeta: 475 *