Abstract
Solid solution e ects on thermal conductivity within the MgO-Al2O3-Ga2O3 system were studied.
Samples with systematically varied additions of MgGa2O4 to MgAl2O4 were prepared and the laser
ash technique was used to determine thermal di usivity at temperatures between 200C and 1300C.
Heat capacity as a function of temperature from room temperature to 800C was also determined using
di erential scanning calorimetry. Solid solution in the MgAl2O4-MgGa2O4 system decreases the thermal
conductivity up to 1000C. At 200C thermal conductivity decreased 24% with a 5 mol% addition of
MgGa2O4 to the system. At 1000C the thermal conductivity decreased 13% with a 5 mol% addition.
Steady state calculations showed a 12.5% decrease in heat
ux with 5 mol% MgGa2O4 considered across
a 12 inch thickness.
