Titre du document / Document title

Calzirtite after tetragonal ZrO₂ studied by transmission electron microscope

Auteur(s) / Author(s)

LIN J.-S. ⁽¹⁾ ; SHEN P. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung, 804, TAIWAN, PROVINCE DE CHINE

Résumé / Abstract

Reactive sintering of CaO, ZrO₂, and TiO₂ (2:5:2 in molar ratio) powders at 1320°c for 2 weeks caused the topotaxial formation of calzirtite (Ca₂Zr₅Ti₂O₁₆, a 3 x 3 x 2 fluorite superstructure denoted as czt) after ZrO₂ nuclei, presumably of tetragonal (t-) symmetry with an orientational relationship [100]_t//[100]_czt; [001]_t//[001]_czt. To maintain a t-ZrO₂ precursor for the subsequent calzirtite formation, it was essential to have Ti⁴⁺ dissolved faster than Ca²⁺ in the ZrO₂ lattice. The calzirtite grains thus formed have no twin variants but have ordered domains and a new supercell which can be indexed as an 6 x 3 x 4 array of the fluorite subcell, due to ordering of two closely spaced M(1) positions (0.93Ti + 0.07Zr, determined by Rossell). The 6 x 3 x 4 supercell appeared as disk-like variants in the calzirtite matrix.

Revue / Journal Title

Journal of solid state chemistry   ISSN 0022-4596   CODEN JSSCBI 

Source / Source

1996, vol. 126, n^o2, pp. 177-183 (18 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, San Diego, CA, ETATS-UNIS  (1969) (Revue)

Mots-clés anglais / English Keywords

Experimental study ; Chemical preparation ; Powder sintering ; Reaction sintering ; Quaternary compounds ; Topotactic reaction ; Calcium oxides ; Zirconium oxides ; Titanium oxides ; Superstructure ; Microstructure ; TEM ; Crystal structure ; Synthetic mineral ; Inorganic compounds ; Transition element compounds ;

Mots-clés français / French Keywords

Etude expérimentale ; Préparation chimique ; Frittage poudre ; Frittage réactif ; Composé quaternaire ; Réaction topotactique ; Calcium oxyde ; Zirconium oxyde ; Titane oxyde ; Surstructure ; Microstructure ; TEM ; Structure cristalline ; Minéral synthétique ; Ca2Zr5Ti2O16 ; Ca O Ti Zr ; Composé minéral ; Métal transition composé ;

Mots-clés espagnols / Spanish Keywords

Sinterización polvo ; Sinterización reactivo ; Reacción topotáctica ; Superestructura ; Mineral sintético ;

Localisation / Location

INIST-CNRS, Cote INIST : 14677, 35400006718259.0050