LOW-FREQUENCY DIELECTRIC DISPERSION AND PYROEFFECT AT PHASE TRANSITION FOR MONOCLYNIC TELLURIUM ACID AMMONIUM PHOSPHATE CRYSTAL. I.A.Smirnova, N.N.Bolshakova*, N.D.Gavrilova Moscow State University, Moscow, Russia, *Tver State University, Tver, Russia
In this paper temperature dependencies of pyroelectrical effect and low-frequency dielectrical dispersion of monoclynic Tellurium Acid Ammonium Phosphate crystal (TAAP) Te(OH)2*2NH4H2PO4*(NH4)2HPO4 (Tc=318K) in frequency range 20Hz-10kHz and temperature region 220-320K were investigated. Temperature dependence of pyrocoefficient is unusial for ferroelectric crystals - the peak has a 40K shift to ferroelectric phase and has a diffuse shape. We connect it with the turn of crystal cell total dipole moment, in which, probably, hydrogen bonds play important role. Dielectric dispersion data were used to test the "universal law" of dielectric response; parameters n and m were estimated.
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