New Inhomogeneous Ferroelectric Cu(In0.7Cr0.3)P2S6 Crystal with Ferroelectric and Dipolar Glass Coexistence

Abstract

Dielectric properties of new Cu(In 0.7 Cr 0.3 )P 2 S 6 crystals were investigated in the temperature range 100 < T < 350 K and frequency range 20 Hz < ν < 3 GHz. A smeared ferroelectric phase transition is observed in presented crystal around T c ≈ 245 K. The ferroelectric phase transition is characterized as second order, “order-disorder” phase transition. At low temperatures, the freezing phenomena in Cu(In 0.7 Cr 0.3 )P 2 S 6 revealed the complex dielectric permittivity behavior characteristic for the transition into the dipolar glass state. The activation energy of this low temperature process was found to be E = 145.4 meV and the freezing temperature was estimated to be 28.6 K.