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FIZIKA A 14 (2005) 1 , 19-28
 
X-RAY DIFFRACTION STUDY OF THERMAL PROPERTIES OF TITANIUM DIOXIDE
STANKO POPOVIĆ a, ŽELJKO SKOKOa, ANDREJA GAJOVIĆ b,
KREŠIMIR FURIĆ b and SVETOZAR MUSIĆ b
aPhysics Department, Faculty of Science, University of
Zagreb, Bijenička cesta 32, HR-10002 Zagreb, POB 331, Croatia
E-mail addresses: spopovic@phy.hr, zskoko@phy.hr
bRuđer Bošković Institute, POB 180, 10002 Zagreb, Croatia
Received 31 January 2005; revised manuscript received 14 April
2005
Accepted 2 May 2005 Online 21 October 2005
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.
PACS numbers: 61.50.Ks, 64.70.Kb, 65.40.De, 65.70
UDC 548.73
Keywords: titanium dioxide, rutile, anatase, phase transition, thermal expansion,
X-ray powder diffraction
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