XPS study of the phase transition in pure zirconium oxide nanocrystallites

• Published in: Applied surface science Vol. 252; no. 5; pp. 1651 - 1656
• Main Authors: Tsunekawa, S., Asami, K., Ito, S., Yashima, M., Sugimoto, T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-12-2005; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Critical size; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Gel–sol method; Ionic valence; Nanocrystallite; Oxygen deficiency; Phase transition; Physics; Zirconium oxide; 61.66.Fn; 81.07.Bc; Zirconium oxide; Critical size; Ionic valence; 79.60.−i; Nanocrystallite; 64.70.Nd; Gel–sol method; Phase transition; Oxygen deficiency; Oxygen; Phase transformations; 81.07.Bc Zirconium oxide; Valence; Zirconium oxides; 79.60.-i; Sol-gel process; X-ray photoelectron spectra; Gel-sol method
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2005.03.183

Pure zirconium oxide nanocrystallites with diameters 6–140
nm are fabricated from ultrafine metallo-organic complexes by thermal hydrolysis at 120
°C and/or heat treatment at 125–1025
°C. X-ray photoelectron spectroscopy shows that effective ionic valence of Zr decreases with decreasing particle diameter. The size dependence of the ionic valences suggests that the phase transition from cubic to tetragonal occurs at an effective Zr valence of 2.0 near 3
nm in diameter and that the phase transition from tetragonal to monoclinic takes place at a critical size of 25
nm diameter with an effective Zr valence of about 2.6.