Heat capacities and thermal conductivities of AmO2 and AmO1.5

The thermal diffusivity of AmO2 was measured from 473 to 773 K and that of AmO1.5 between 473 and 1373 K using a laser flash method. The enthalpy increment of AmO2 was measured from 335 to 1081 K and that of AmO1.5 between 335 and 1086 K using drop calorimetry. The heat capacities of AmO2 and AmO1.5 were derived from the enthalpy increment measurements. The thermal conductivity was determined from the measured thermal diffusivity, heat capacity and bulk density. The heat capacities of AmO2 was found larger than that of AmO1.5. The thermal conductivities of AmO2 and AmO1.5 were found to decrease with increasing temperature in the investigated temperature range. The thermal conductivity of AmO1.5 with A-type hexagonal structure was smaller than that of AmO2 with C-type fluorite structure but larger than that of sub-stoichiometric AmO1.73.