Microwave anisotropy and dichroism of ferroelectric crystals CH3NH3HgCl3

Abstract

Microwave dielectric anisotropy of oriented crystals of CH3NH3HgCl3 is measured by a resonant cavity method at 9.5 GHz. A general expression for the perturbation cavity is given, taking into account anisotropies of the electrical properties and of the depolarisation factor of the sample. Measurements of the frequency shift and transmitted power are made versus crystal orientation relative to the microwave field. Using the general formulas established in this work, the complex permittivity tensor is calculated (at 9.5 GHz and 300 K): εc = 22.0 – j 2.60, εa = 22.0 – j 0.40 (a ⊥ c).