Thermodynamics Research Center / ThermoML | Thermochimica Acta

Characterization of thermal conductivity of SiO2-Al2O3-Y2O3 glasses

Samal, S.[Sneha], Lee, J.[Jungki], Jeong, D.-Y.[Dae-Yong], Kim, H.[Hyungsun]
Thermochim. Acta 2015, 604, 1-6
ABSTRACT
The thermal properties of SiO2-Al2O3-Y2O3 glasses were investigated within a temperature range of 25 800 C. This found that glass with a composition of 24Y2O3.21Al2O3.55SiO2 exhibits a thermal conductivity of 1.04W/mK at room temperature, and thermal conductivity increases with temperature due to an increase in the amount of bridging oxygen. The thermal conductivity of glasses with a composition of xY2O3.21Al2O3.(79-x)SiO2, on the other hand, decreased with an increase in either the Y2O3 content or Al2O3/SiO2 ratio. This decrease in thermal conductivity was analyzed with respect to the decrease in phonon mean free path resulting from the increased non-bridging oxygen content, which revealed 24Y2O3.21Al2O3.55SiO2 to have the maximum thermal conductivity of 1.7W/mK at 800 C. Glass systems incorporating yttria can therefore be considered suitable sintering additives for highly thermally conducting ceramics such as silicon nitride.
Compounds
# Formula Name
1 O2Si silicon dioxide
2 O3Y2 yttrium oxide (Y2O3)
3 Al2O3 aluminum oxide (Al2O3)
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 2
  • 3
  • 1
  • Thermal diffusivity, m2/s ; Glass
  • Temperature, K; Glass
  • Mole fraction - 3; Glass
  • Mole fraction - 2; Glass
  • Pressure, kPa; Glass
  • Glass
  • Laser flash apparatus
  • 50
  • POMD
  • 2
  • 3
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Glass
  • Temperature, K; Glass
  • Mole fraction - 3; Glass
  • Mole fraction - 2; Glass
  • Pressure, kPa; Glass
  • Glass
  • Laser pulse heating
  • 50
  • POMD
  • 2
  • 3
  • 1
  • Mass density, kg/m3 ; Glass
  • Mole fraction - 3; Glass
  • Mole fraction - 2; Glass
  • Temperature, K; Glass
  • Pressure, kPa; Glass
  • Glass
  • Pycnometric method
  • 5