Intrinsic microwave dielectric loss of lanthanum aluminate

The intrinsic dielectric properties of LaAlO₃ were investigated in order to understand the microwave properties for several material containing LaAlO₃. LaAlO₃ single crystal was the prepared by Czochralski method. The temperature dependence of the dielectric properties and neutron inelastic scattering of the single crystal were measured. From these data, the intrinsic dielectric properties were evaluated and it was found that the dielectric loss of the LaAlO₃ includes two types of dielectric loss. One is a phonon absorption related loss and the other is the loss arising from Debye type orientation polarization. The latter affects the room temperature dielectric loss in LaAlO₃ containing materials. The present study suggested that removing this polarization loss is important to decrease the total dielectric loss.