No abstract

Lead-free single crystal, (K, Na, Li)(Nb, Ta)O3:Mn, was successfully grown using top-seeded solution growth method. Complete matrix of dielectric, piezoelectric and elastic constants for [001]C poled single crystal was determined. The piezoelectric coefficient d33 measured by the resonance method was 545 pC/N, which is almost three times that of its ceramic counterpart. The values measured by the Berlincourt meter ( d33∗=6300.16667empC/normalN) and strain-field curve ( d33∗∗=8700.16667empm/normalV) were even higher. The differences were assumed to relate with the different extrinsic contributions of domain wall vibration and domain wall translation during the measurements by different approaches, where the intrinsic contribution (on the order of 539 pm/V) was supposed to be the same. The crystal has ultrahigh electromechanical coupling factor (k33 ~ 95%) and high ultrasound velocity, which make it promising for high frequency medical transducer applications.

A high quality lead-free (Li, Ta) modified (K, Na)NbO 3 single crystal and its complete set of elastic, dielectric and piezoelectric coefficients with macroscopic 4mm symmetry

Mn modified 0.26Pb(In 1/2 Nb 1/2 )O 3 À0.42Pb(Mg 1/3 Nb 2/3 )O 3 À0.32PbTiO 3 (PIN-PMN-PT:Mn) single crystals with orthorhombic perovskite crystal structure were polarized along [011] direction, resulting in the single domain state "1O." The complete set of material constants was determined using the combined resonance and ultrasonic methods. The thickness shear piezoelectric coefficient d 15 and electromechanical coupling factor k 15 were found to be on the order of 3100 pC/N and 94%, respectively, much higher than longitudinal d 33 $ 270 pC/N and k 33 $ 70%. Using the single domain data, the rotated value of d 33 * along [001] direction was found to be 1230 pC/N, in agreement with the experimentally determined d 33 value of 1370 pC/N, conferring extrinsic contributions being about 10%, which was also confirmed using the Rayleigh analysis. In addition, the mechanical quality factors Q m were evaluated for different "1O" vibration modes, where the longitudinal Q m was found to be $1200, much higher than the value for "4O" crystals, $300. V C 2012 American Institute of Physics. [http://dx