Combustion synthesis and properties of fine-particle rare-earth-metal zirconates, Ln2Zr2O7

• Published in: Journal of materials chemistry Vol. 3; no. 12; pp. 1289 - 1294
• Main Authors: ARUL DHAS, N, PATIL, K. C
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 1993
• Subjects: Chemistry; Elements and non-metal compounds (oxides, hydroxides, hydrides, sulfides, carbides, ...); Exact sciences and technology; Inorganic chemistry and origins of life; Preparations and properties; Ternary compound; Fluorescence spectrum; Scanning electron microscopy; Particle size; Transition metal Compounds; Combustion; X ray diffraction; Fine particle; Preparation; Zirconates; Zirconium Oxides; Infrared spectrum; Lanthanide Oxides
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/JM9930301289

Fine-particle rare-earth-metal zirconates, Ln2Zr2O7, where Ln = La, Ce, Pr, Nd, Sm, Gd and Dy having the pyrochlore structure were prepared using a novel combustion process. The process employs aqueous solutions of the corresponding rare-earth-metal nitrate, zirconium nitrate and carbohydrazide/urea in the required molar ratio. When the solution is rapidly heated to 350-500 C it boils, foams and burns autocatalytically to yield voluminous oxides. The formation of single-phase Ln2Zr2O7 was confirmed by powder XRD, infrared and fluorescence spectroscopy. The solid combustion products are fine, having surface areas in the range 6-20 m2/g. The cold pressed Pr2Zr2O7 compact, when sintered at 1500 C, 4 h in air, achieved 99% theoretical density. 24 refs.