Dielectric and electrical properties of AgCrP₂S₆ and Cu_0.2Ag_0.8CrP₂S₆ layered crystals

ABSTRACT

The dielectric properties of newly synthesized AgCrP₂S₆ and Cu_0.2Ag_0.8CrP₂S₆ phosphorous chalcogenide crystals are presented. The measurements were performed in the frequency and temperature ranges 20 Hz to 1 MHz and 110 K to 470 K, respectively. No anomalies of complex dielectric permittivity indicating the polar phase transition can be detected in the measured temperature range. Dielectric spectra at high temperatures are mostly influenced by the electrical conductivity. From DC conductivity the activation energies have been calculated and compared with CuCrP₂S₆. The activation energies of the conductivity were found to be 1.26 eV and 0.75 eV for AgCrP₂S₆ and Cu_0.2Ag_0.8CrP₂S₆, respectively.

KEYWORDS:

• Ferroelectricity
• thiophosphates
• dielectric permittivity
• electrical conductivity
• layered crystals

Funding

This work was financially supported by the Research Council of Lithuania (project no. TAP-LU-15-005).