hrvatski jezikClear Cookie - decide language by browser settings

In situ phase analysis of the thermal decomposition products of zirconium salts

Štefanić, Goran; Gržeta, Biserka; Popović, Stanko; Musić, Svetozar (1999) In situ phase analysis of the thermal decomposition products of zirconium salts. Croatica Chemica Acta, 72 (2-3). pp. 395-412. ISSN 0011-1643

[img] PDF - Published Version
Download (169kB)

Abstract

X-ray powder diffraction at high temperature was used to determine the phase composition of the thermal decomposition products of two zirconium salts, Zr(SO4)(2). 4H(2)O and ZrO(NO3)(2). 2 H2O, and of a mixture of zirconium nitrates having Zr(OH)(2)(NO3)(2). 4.7 H2O and ZrO(NO3)(2). 2H(2)O as dominant components. Heating of the samples up to 1200 degrees C was performed inside a high-temperature chamber, attached to a diffractometer, at an air pressure of approximate to 2 x 10(-3) Pa. Regardless of the structural differences in the starting salts, thermal decomposition products crystallized to t-ZrO2 which remained stable up to 1200 degrees C. This result indicated that the structural nature of the starting materials was not the most important factor of metastable t-ZrO2 formation. The thermodynamically stable m-ZrO2 appeared after the cooling of the samples to room temperature. If the cooling was performed at low air pressure, the m-ZrO2 content was small. Introduction of air, even at RT, caused a considerable increase of m-ZrO2, which became the dominant phase in all cases. The important role of oxygen in the t-ZrO2 --> m-ZrO2 transition indicates that the lack of oxygen in the zirconia lattice favours the formation of metastable t-ZrO2.

Item Type: Article
Uncontrolled Keywords: t-ZrO2; m-ZrO2; X-ray diffraction; in situ phase analysis; phase transitions; lattice defects; low-temperature t-zro2; x-ray-diffraction; tetragonal zro2; crystal phases; crystallization; transformation; powder; stabilization; scattering; stability
Subjects: NATURAL SCIENCES > Chemistry
Divisions: Division of Materials Chemistry
Division of Materials Physics
Projects:
Project titleProject leaderProject codeProject type
Sinteza i mikrostruktura metalnih oksida i oksidnih stakalaSvetozar Musić00980903MZOS
Depositing User: Goran Štefanić
Date Deposited: 25 Nov 2013 15:05
Last Modified: 28 Feb 2014 12:56
URI: http://fulir.irb.hr/id/eprint/1120

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year