Size effect of trivalent oxides on low temperature phase stability of 2Y-TZP

• Published in: Journal of materials science Vol. 36; no. 22; pp. 5391 - 5395
• Main Authors: JANG, Ju-Woong, KIM, Dae-Joon, DEUK YONG LEE
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 15.11.2001; Springer Nature B.V
• Subjects: Alloying effects; Cations; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystalline state (including molecular motions in solids); Crystallographic aspects of phase transformations; pressure effects; Dopants; Exact sciences and technology; Lattice parameters; Lattice vibration; Low temperature; Materials science; Phase stability; Physics; Raman spectra; Size effects; Solid solution hardening, precipitation hardening, and dispersion hardening; aging; Solid solution, precipitation, and dispersion hardening; aging; Structure of solids and liquids; crystallography; Tetragonal zirconia polycrystals; Treatment of materials and its effects on microstructure and properties; Zirconium; Raman spectra; Inorganic compounds; Tetragonal lattices; Phase transformations; Thermal ageing; Transition element compounds; Crystal chemistry; Doped materials; Stabilized zirconia; XRD; Ionic radius; Experimental study; Heat treatments; Characterization; Rare earths; Zirconium oxides; Size effect; Trivalent metal; Phase stability; Yttrium oxides
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/A:1012409009280

2 mol% Y2O3stabilized-TZPs (2Y-TZPs) doped with oversized trivalent cations (Sc3+< Yb3+< Y3+< Sm3+< Nd3+< La3+) whose ionic radius is larger than Zr4+was sintered for 1 h at 1500°C over the range containing trivalent oxides from 0 to 2 mol% with 0.5 mol% interval to evaluate the effect of trivalent cation alloying on low temperature phase stability of 2Y-TZP by investigating the variation of Raman spectra and lattice parameters. For a given concentration of dopant, tetragonality (c/aaxial ratio) increases with raising the dopant size. However, monoclinic (m)-ZrO2content for the specimens annealed for 500 h at 220°C in air firstly decreases with increasing dopant size and then increases as dopant size is greater than Y3+ion. Raman modes of Zr-OII(260 cm−1) and Zr-OI(640 cm−1) shift to higher wavenumbers only when Sm2O3, Nd2O3, and La2O3are added. Although full width at half maximum (FWHM) of 640 cm−1is constant, FWHM of 260 cm−1mode decreases with increasing dopant size, indicating that an ordered structure (pyrochlore phase) may be formed. Therefore, dopant size is dependent on phase stability of 2Y-TZP in this system.