Preparation and dielectric properties of high Tc relaxor-based single crystals

Single crystals of the xPB(Sc(1/2)Nb(1/2))O(3-y)Pb(Zn(1/3)Nb(2/3))O(3-z)PbTiO(3)(PSZNT) and xPb(In(1/2)Nb(1/2))O(3-y)Pb(Zn(1/3)Nb(2/3))O(3-z)PbTiO(3) (PIZNT) ternary systems have been synthesized by a flux method using PbO flux. The single crystals were grown in a Pt crucible by a mass crystallization, achieved by slow cooling of the 55PbO.45PSZNT or PIZNT molten solution with 1.5-3degreesC/h from 1,230-1,250degreesC to 850degreesC. The resulting crystals are 2-5 mm in length and dark brown perovskite. For the PSZNT10/75/15(mol%) system, the (001) single crystal near the morphotropic phase boundary, showed a room temperature dielectric constant after poling of 2,700 and a very low dielectric loss of 0.5%. A maximum dielectric constant leached to 22,000 at 216degreesC. On the other hand, the PIZNT10/77/13(mol%) system showed Tc=222degreesC, epsilon (r) =3,900 at 20degreesC and epsilon (r) =14,000 at Tc.