Radio-frequency dielectric relaxation in KH2PO4 and some isomorphic arsenates

Measurements of the dielectric response in the 5-80 MHz range are reported for KH 2 PO 4 , KH 2 AsO 4 and CsH 2 AsO 4 at temperatures close to their ferroelectric transition. The results reveal a dielectric loss mechanism in the paraelectric phase of CsH 2 AsO 4 and a pronounced Debye relaxation process in the ferroelectric phase close to the transition temperature for all three materials.