17O NMR investigation of hafnia and ternary hafnium oxides

• Published in: Journal of materials chemistry Vol. 6; no. 12; pp. 1951 - 1955
• Main Authors: BASTOW, T. J, SMITH, M. E, WHITFIELD, H. J
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 1996
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth from solid phases (including multiphase diffusion and recrystallization); Materials science; Methods of crystal growth; physics of crystal growth; Physics; Noncrystalline structure; Hafnium oxides; Crystallization; Binary systems; Amorphous state; XRD; Experimental study; Heat treatments; Magic angle; Chemical shift; Silicon oxides; Gel growth; NMR spectra; Germanium oxides; Amorphous state structure; Crystal structure
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/JM9960601951

Structural evolution in alkoxide-derived amorphous HfO2 gels was followed by 17O magic angle spinning (MAS) NMR in 17O-enriched samples, with crystallisation being identified readily at 500 C. A series of 17O-enriched alkali-metal and alkaline-earth-metal hafnates with sodium chloride- and perovskite-related structures were also examined by 17O MAS NMR spectroscopy. The number of oxygen resonances is related to the crystal structure. Comparison of 17O NMR data is made to isostructural zirconium-containing compounds with the isotropic chemical shifts (Hf/Zr) in the ratio 0.86 plus or minus 0.02. 17O NMR data are also presented from HfO2-SiO2 and HfO2-GeO2 gel mixtures. 14 refs.