arXiv subjects

A. P. Moina

Publications and source records attributed to A. P. Moina.

20 records · Page 2Linked to original sources

arXiv2000

Longitudinal Field Influence on the Phase Transition and Physical Properties of the Kh2po4 Family Ferroelectrics

We verify whether the previously developed model of a KD2PO4 crystal, with the shear strain eps6 taken into account, is able to describe the longitudinal electric field E3 influence on the KH2PO4 family ferroelectrics. Major effects of the strain eps6 are splitting of the Slater energies of the short-range correlations and the effective field created by piezoelectric coupling. Calculated TC-E3 phase diagrams, field dependences of polarization, susceptibility, and elastic constant of deuterated KD2PO4 and pure KH2PO4 well accord with the available experimental data. For a consistent description of all dielectric and piezoelectric characteristics of the crystals, phonon degrees of freedom must be taken into account.

cond-mat.mtrl-sci↗

arXiv1999

Influence of shear stress $σ_6$ on the phase transition and physical properties of KD2PO4 type ferroelectrics

Within the four-particle cluster approximation for the proton ordering model we study the influence of shear stress $σ_6$ on the phase transition, static dielectric, elastic and thermal properties of deuterated KD2PO4 type ferroelectrics. Thermodynamic potentials and physical characteristics of the crystals in the presence of stress $σ_6$ are calculated. Numerical analysis of the obtained results is performed, and the set of the theory parameters providing the best fit to the available experimental data is found. The $Tc-σ_6$ phase diagram is constructed; temperature dependences of the calculated quantities are studied, possible stress dependences are indicated. Influence of $σ_6$ stress is analogous to that of electric field conjugate to the order parameter.

cond-mat↗