Naslov
Thermal expansion between 480 and 940 ^oC of Cr-doped mullites derived from single-phase precursors

Autori
Gržeta, Biserka ; Tkalčec, Emilija ; Popović, Jasminka ; Ivanković, Hrvoje

Izvornik
American Mineralogist (0003-004X) 92 (2007), 2-3; 412-415

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
thermal expansion; mullite; chromium doping; X-ray diffraction; fitting methods

Sažetak
The lattice parameters were determined by in situ X-ray powder diffraction between room temperature (RT) and 940 ^oC for the Cr-doped mullite derived from single-phase precursors containing up to 9.60 wt% Cr_2O_3. Mullites were orthorhombic, space group Pbam. Chromium doping caused the increase in unit-cell parameters. Strongest expansion caused by Cr incorporation into mullite was noticed along the c-axis followed by a and b. In temperature region from 480 to 940 ^oC the lattice parameters a, b, and c expanded almost linearly, and the linear coefficients of thermal expansion along crystallographic axes were calculated for this region. Strongest expansion caused by the thermal treatment was noticed along the b-axis followed by c and a. The linear thermal expansion coefficients were also dependent on the chromium content in mullite. All thermal expansion coefficients, alpha(a), alpha(b) and alpha(c), exhibited minima for 6.97 wt% Cr_2O_3.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemijsko inženjerstvo

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