Piezoelectric and elastic properties of layered materials of Cu(In,Cr)P2(S,Se)6 system

Abstract

In this contribution, we present new results of ultrasonic and piezoelectric investigation in layered materials of Cu(In,Cr)P 2 (S,Se) 6 system including the phase transitions points. It was shown, that in low temperature phase the electromechanical coupling parameters substantially increased after polarization of the material. The large anisotropy of linear and nonlinear elastic properties was observed. The largest critical ultrasonic attenuation anomalies appeared for ultrasonic wave propagating normal to layers: i.e. along polarization direction. From measurements of the amplitude of second longitudinal ultrasonic harmonic we showed that these layered crystals have extremely high elastic nonlinearity in the direction normal to layers. DC bias electric field induced piezoelectricity due to electrostiction was observed in the paraelectric phase of pure materials and their solid solutions. The piezoelectric memory was observed after samples were kept for long time in DC electric field along polar axis at fixed temperature in the paraelectric phase.

Phase Transitions in Layered Semiconductor - Ferroelectrics

“…Ultrasonic investigations were performed by automatic computer controlled pulse-echo method and the main results are presented in papers (Samulionis et al, 2007;Samulionis et al, 2009a;Samulionis et al, 2009b). Usually in CuInP 2 S 6 family crystals ultrasonic measurements were carried out using longitudinal mode in direction of polar c-axis across layers.…”

“…Usually in CuInP 2 S 6 family crystals ultrasonic measurements were carried out using longitudinal mode in direction of polar c-axis across layers. The pulse-echo ultrasonic method allows investigating piezoelectric and ferroelectric properties of layered crystals (Samulionis et al, 2009a). This method can be used for the indication of ferroelectric phase transitions.…”

Ultrasonic and Dielectric Studies of Polyurea Elastomer Composites with Inorganic Nanoparticles

“…Two The ultrasonic measurements were carried out using the methods that we previously developed for such measurements for layered ferroelectrics [16][17]. Pulse-echo automatic time-of-flight technique was applied at 10 MHz frequency.…”

Phase Transitions in Smectic Bent-Core Main-Chain Polymer Networks Detected by Dielectric and Ultrasonic Techniques

“…There are not so many ultrasonic measurements especially at high frequencies in polymeric materials [8]. It might also be of interest the detection of piezoelectric sensitivity in BCLC by ultrasonic method as for inorganic lamellar crystals of the CuInP 2 S 6 family [9][10][11].…”