Pyroelectric properties of natural natrolite Na/sub 2/Al/sub 2/Si/sub 3/O/sub 10/ /times/ 2H/sub 2/O

The authors have investigated single natrolite crystals from the Khibinsk and Lovozersk alkaline massifs of the Kola peninsula. The pyroelectric coefficient ..gamma.. was measured by the static method using temperature steps of 2-3 K and graphic registration of the pyroelectric current. The dielectric constant epsilon and the tangent of the angle of dielectric losses tan delta were determined. Based on the presented values of ..gamma..(T) and epsilon(T) in comparison with the known values for lithium sulfate monohydrate, barium nitrite, and cancrinite, natrolite can be considered as a weak linear pyroelectric.