EPR study of Mo{sup V} in the tetragonal and monoclinic phases of zirconia

Journal Article · Sun Mar 01 04:00:00 EST 1998 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1997.7699· OSTI ID:642172

Cordischi, D; Occhiuzzi, M; Dragone, R ^[1]

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1. Univ. La Sapienza, Rome (Italy). Dept. di Chimica

MoO{sub x}/ZrO{sub 2} ({sup 95}Mo-enriched or not) samples were prepared by adsorption or coprecipitation and were subsequently heated in air or oxygen at 773 or 1,073 K. Depending on the heating temperature and the Mo content, clustered Mo{sup V} species (Mo{sub clust}{sup V}) and isolated Mo{sup V} species in tetragonal (Mo{sub tetr}{sup V}) and/or monoclinic (Mo{sub mon}{sup V}) phases were formed. Mo{sup V} species were detected by EPR only at low temperature (77 K), were formed by treatments in oxidizing conditions, and were insensitive to leaching treatment. Computer simulation of the spectra yielded the following spin-Hamiltonian parameters for isolated species: g{sub {parallel}} = 1.960, g{sub {perpendicular}} = 1.843, A{sub {parallel}} = 34 G, and A{sub {perpendicular}} = 90 G for Mo{sub tetr}{sup V}; g{sub xx} = 1.803, g{sub yy} = 1.883, g{sub zz} = 1.965, A{sub xx}= 81 G, A{sub yy} = 61 G, and A{sub zz} = 16 G for Mo{sub mon}{sup V}. The ground state, spin polarization factor, and spin-orbit reduction factor were calculated by the equations of McGarvey.

• OSTI ID: 642172
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 136; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL COMPOSITION
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
HEAT TREATMENTS
MOLYBDENUM OXIDES
MONOCLINIC LATTICES
PHASE STUDIES
TETRAGONAL LATTICES
X-RAY DIFFRACTION
ZIRCONIUM OXIDES