Specific Heat and Thermal Diffusivity and Conductivity of PbWO4 Single Crystal Related to Its Crystal Orientation at (300 to 673) K

Lead tungstate (PbWO4, PWO) single crystal has been chosen as a new generation scintillation material. The specific heat and thermal diffusivity of PWO single crystal grown by the vertical Bridgman technique is investigated for the first time by differential scanning calorimetry (DSC) and a laser flash technique at (300 to 673) K, respectively. The thermal conductivity is calculated, and it exhibits anisotropy with the values along the [100] axis (Kx,y) higher than that along the [001] axis (Kz), which is 2.40 W·m−1·K−1 and 2.00 W·m−1·K−1 at room temperature, respectively. Because of the heavier elements of the Pb atom, the PWO crystal has a higher degree of anharmonicity of lattice vibrations and thus has a smaller thermal conductivity than another scintillation material bismuth germanate (BGO).