Dielectric constant of mercuric iodide

Abstract
The dielectric constant of mercuric iodide (HgI2) in the form of single crystals has been measured both parallel and perpendicular to the c axis. The dependence of the dielectric constant on temperature in the range 300K to 100K has been investigated. This reveals a lowering of dielectric constant with temperature from a value of 10.4 at 300K to 4.0 at 110K. The values of the dielectric constant in both directions are nearly the same, indicating that there is very little anisotropy in HgI2 crystals.