EFFECT OF THERMAL ANNEALING ON THE DIELECTRIC-PROPERTIES OF KTIOPO4 SINGLE-CRYSTALS

Dielectric properties of potassium titanyl phosphate have been investi gated as a function of thickness and frequency, as well as annealing t reatment under various atmospheres. The low frequency dielectric const ant of KTP crystals is shown to depend upon the sample thickness, and this feature is attributed to the existence of surface layers. The fre quency-dependent dielectric response of KTP exhibits a non-Debye type relaxation, with a distribution of relaxation times. The dielectric be havior of KTP samples annealed in various atmospheres shows that the l ow frequency dielectric constant is influenced by the contribution fro m the space charge layers. Prolonged annealing of the samples leads to a surface degradation, resulting in the formation of a surface layer of lower dielectric constant. This surface degradation is least when a nnealed in the presence of dry oxygen. From the analysis of the dielec tric data using complex electric modulus, alpha(m) has been evaluated for the virgin and annealed samples. (C) 1996 American Institute of Ph ysics.