Effects of Manganese Oxides/Gold Composite Electrode on Piezoelectric Properties of Lead Magnesium Niobate Titanate Single Crystal

We have confirmed a high dielectric constant after poling epsilon(T)(33)/epsilon(0) of 7700 and piezoelectric constant d(33) = 2250 pC/N, which are 40% larger than those of the initial sample, for a lead magnesium niobate-lead titanate 0.72 Pb(Mg(1/3)Nb(2/3))O(3)-0.28 PbTiO(3) single crystal plate with a manganese oxide/gold (Au) composite electrode. The increased epsilon(T)(33)/epsilon(0) and d(33) may be attributable to the smaller domains realized by fine patterning semiconductor manganese oxide and conductive Au composite electrodes on the single crystal plate. The use of a semiconductor/conductor composite electrode is an effective method of improving the properties of piezoelectric single-crystal transducers. (C) 2011 The Japan Society of Applied Physics