Journal of Crystal Growth, Vol.226, No.1, 111-116, 2001
Growth and electrical properties of Pb(Sc1/2Nb1/2)O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3 ternary single crystals by a modified Bridgman technique
Single crystals of 0.05Pb(Sc1/2Nb1/2)O-3-0.63Pb(Mg1/3Nb2/3)O-3-0.32PbTiO(3) have been grown directly from melt by a modified Bridgman technique. The crystals with perovskite structure were 15 mm in diameter and 20 mm in length. The segregation during the growth of the single crystals was studied by means of X-ray diffraction analysis. The results show that PbTiO3 content increases throughout the crystal growth. The electrical properties of the single crystals oriented along the [001] axis have been characterized. The plates cut from the seed end of a boule exhibited a permittivity (epsilon (33)/epsilon (0)) of about 3500, dielectric loss tangent (tg delta)<1%, dielectric constant peaks at 162 degreesC:, piezoelectric constant (d(33)) approximate to 1200 pC/N, and electromechanical coupling factor (k(t)) approximate to 60% for the thickness mode. Our results show that xPb(Sc1/2Nb1/2)O-3-gamma Pb(Mg1/3Nb2/3)O-3-(1-x-gamma )PbTiO3 single crystals are promising for a wide range of electromechanical transducer applications.
Keywords:segregation;Curie temperature;growth from melt;single crystal growth;perovskites;piezoelectric materials