Piezo-/ferroelectric crystals of a new Pb(Yb 1/2 Nb 1/2 )O 3 -Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 ternary solid solution system with the dimensions of 30 Â 30 Â 12 mm 3 have been grown by the top-seeded solution growth method for the first time. The crystal structure is analyzed by means of X-ray diffraction at various temperature. The composition of the grown crystals is found to be near the ternary morphotropic phase boundary. The Curie temperature T C reaches 205°C. The piezoelectric coefficient d 33 and the longitudinal electromechanical coupling factor k 33 are found to be 1800 pC/N and 90%, respectively. A remanent polarization Pr of 27.8 μC/cm 2 is displayed with a coercive field E c of about 7 kV/cm. These results show that the PYMNT crystals exhibit a higher T C and a larger coercive field than the binary PMN-PT piezocrystals, making this material a promising candidate for high-power electromechanical transducers that can operate in a wider temperature range.

Reaction of 1,1,1,5,5,5-hexafluoropentane-2,4-dione with (1S,2S)-(-)-1,2-diaminocyclohexane afforded a homochiral Schiff base (1Z,4Z)-2,4-bis(trifluoromethyl)-5a, 6,7,8,9,9a-hexahydro-3H-benzo[b][1,4]diazepine (1). Fluorescent analysis showed that it exhibited an intense emission band at 488 nm when the exciting radiation was set at 437 nm. Crystallographic analysis shows that it belongs to chiral space group C 2 with ferroelectric behavior. A typical ferroelectric feature of electric hysteresis loop was obtained, with remanent polarization (Pr) of ca. 0.01 µC/cm 2 and coercive field (Ec) of 0.27 kV/cm.

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