Low-Frequency Internal Friction in Crystals of the Potassium Dihydrogen Phosphate Family

Abstract

The low-frequency internal friction Q–1 and shear modulus G have been studied by the inverted torsion pendulum method for a series of crystals belonging to potassium dihydrogen phosphate family: KH2PO4, KD2PO4, 0.95KH2PO4–0.05NH4H2PO4, RbH2PO4, RbH2AsO4, and CsH2AsO4. A number of anomalies have been revealed in the temperature dependences Q–1(T) and G(T), both in the ferroelectric and paraelectric phases of these crystals; the nature of these anomalies is discussed.