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

Znanstveni rad - Izvorni znanstveni rad

• Autor: Goran Štefančić
• Autor: Biserka Gržeta
• Autor: Stanko Popović
• Autor: Svetozar Musić
• Autorova ustanova: Sveučilište u Zagrebu; Prirodoslovno-matematički fakultet; (Fizički odsjek)
• Znanstveno / umjetničko područje, polje i grana: PRIRODNE ZNANOSTI; Fizika

Sažetak (engleski)

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 ⋅ 4 H2O and ZrO(N03)2 ⋅ 2 H2O, and of a mixture of zirconium nitrates having Zr(OH)2(NO3)2 ⋅ 4.7 H2O and ZrO(NO3)2 ⋅ 2 H2O as dominant components. Heating of the samples up to 1200 °C was performed inside a high-temperature chamber, attached to a diffractometer, at an air pressure of ≈ 2 × 10-3 Pa. Regardless of the structural differences in the start-ing salts, thermal decomposition products crystallized to t-ZrO2, which remained stable up to 1200 °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 ali 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.

• Ključne riječi (engleski): t-ZrO2; m-ZrO2; X-ray diffraction; in situ phase analysis; phase transitions; lattice defects
• Jezik: engleski
• Vrsta publikacije: Znanstveni rad - Izvorni znanstveni rad
• Status objave: Objavljen
• Vrsta recenzije: Recenziran - međunarodna recenzija
• Verzija publikacije: Objavljena verzija rada (izdavačev PDF)
• Naslov časopisa: Croatica Chemica Acta
• Brojčani podaci: vol. 72, br. 2-3, str. 395-412
• p-ISSN: 0011-1643
• e-ISSN: 1334-417X
• URN:NBN: urn:nbn:hr:217:327313
• Datum objave publikacije: 1999
• URL dokumenta: https://hrcak.srce.hr/132180
• Vrsta resursa: Tekst
• Prava pristupa: Otvoreni pristup
• Datum i vrijeme pohrane: 2019-10-10 09:21:08