The Penn State Research Foundation

Seung-Eek Park

Thomas R Shrout

Clive A Randall

Richard Eitel

Patrick D Lopath

The present invention is directed to a new family of high Curie temperature, morphotropic phase boundary systems, based on the perovskite solid solution having the general formula (1&minus;x)BiMeO -xPbTiO , where Me is a suitably sized cation or combination of cations and x is a molar fraction. The perovskite systems of the present invention offer room temperature properties analogous to, and high temperature properties superior to, commercially available PZT compositions. The perovskite of this invention exhibits a MPB between the rhombohedral and tetragonal phases. Further dopant strategies may be used for property optimization of the perovskite systems.

Perovskite materials for high temperature and high performance actuators and transducers

&lt;001&gt;oriented crystals of lead zinc niobate--lead titanate solid solution (0 to 5 mole % lead titanate) have high electromechanical coupling&gt;85% and exhibit electric field induced phase transition at electric field levels&gt;10.times.Ec (where Ec is the coercive field), resulting in increased transducer driving voltages, decreased fabrication degradation, and high sensitivity/large bandwidth transducer characteristics due to high electromechanical couplings, up to 92%. &lt;001&gt;oriented crystals of lead magnesium niobate--lead titanate solid solution (20 to 50 mole % lead titanate) also exhibit high electromechanical couplings&gt;85% and up to 94%, and thereby can be formed into transducers which exhibit both high sensitivity and large bandwidth.

Relaxor ferroelectric single crystals for ultrasound transducers

An actuator incorporating the invention includes a body of a ferroelectric material. The material is single crystalline and incorporates solid solutions of lead zinc niobate-lead titanate or lead magnesium niobate-lead titanate, described by the formulae: Pb(Zn.sub.1/3 Nb.sub.2/3).sub.1-x Ti.sub.x O.sub.3 and Pb(Mg.sub.1/3 Nb.sub.2/3).sub.l-y Ti.sub.y O.sub.3 l where x and y are defined as 0.ltoreq.x&lt;0.10, and 0.ltoreq.y&lt;0.40. Electrodes enable application of an electric field across the body in a direction that is generally aligned with a &lt;001&gt; crystallographic axis of the ferroelectric material.

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State College, PA, United States of America

Seung-Eek Park