Thermal Conductivity of Calcium Aluminate and Complex Vanadates of Garnet Structure

The thermal conductivity of materials with the nonstoichiometric garnet structure, namely, of calcium aluminate Са 12 Al 14 O 33±δ (both single crystal and ceramic) and doped vanadates Ca 5 Mg 4– x M x (VO 4 ) 6 (M = Zn, Co; 0 ≤ x ≤ 4), in the temperature interval 50–300 K was studied by the steady state comparative-longitudinal thermal flux method. The compositions Ca 5 Mg 4– x Zn x (VO 4 ) 6 , x =1, 3, 4, were studied in the temperature interval 298–573 K by the dynamic method. The effect of the defective structure on the thermal conductivity of the materials was discussed. The thermal conductivity of the materials is ~2 W m –1 K –1 at room temperature and above.