Thermal expansion and glass transition temperature of the rare-earth doped oxynitride glasses

• Published in: Journal of the European Ceramic Society Vol. 24; no. 12; pp. 3377 - 3385
• Main Authors: Lofaj, F., Satet, R., Hoffmann, M.J., de Arellano López, A.R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 2004; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Glass; Glass transition temperature; Glass transitions; Hardness; Oxynitride glass; Physics; Specific phase transitions; Thermal expansion; Thermal properties of amorphous solids and glasses : heat capacity, thermal expansion; Thermal properties of amorphous solids and glasses: heat capacity, thermal expansion, etc; Thermal properties of condensed matter; Thermal expansion; Oxynitride glass; Hardness; Glass transition temperature; Glass; Oxynitrides; Transition temperature; Property composition relationship; Phase transformations; Rare earths Oxides; Doping; Mechanical properties; Experimental study; Density; Thermal properties; Glass transition; Quaternary systems; Silicon Nitrides; Thermal expansion coefficient; Silicon Oxides; Rare earth additions; Magnesium Oxides
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2003.10.012

Thermal expansion coefficients ( α), glass-transition ( T g) and Littleton ( T L) temperatures, hardness and density of the RE–Si–Mg–O–N glasses (RE=Sc, Y, La, Nd, Sm, Gd, Yb, and Lu) were investigated to separate the effects of rare-earth elements and nitrogen on the properties of bulk glasses. These properties depend approximately linearly on nitrogen content, density of the glass and ionic radius of the corresponding lanthanide. Lanthanides modify hardness of the studied oxynitride glasses with 20–24 eq.% N by 11.4–14.4%, α by ∼13%, T g by 31–35 °C, and T L by 33–43 °C. Deviations from linearity found in Nd-, Sm- and Yb-doped glasses were possibly due to valence change. Non-lanthanide dopants, Sc and Y, often do not fit the dependence but result in comparable properties. The effects of nitrogen and rare-earth dopants are independent and additive.