Electrostrictive ceramics for underwater transducer applications

Abstract

The electromechanical properties of two electrostrictive materials designed for use in underwater acoustic applications are determined as functions of temperature and electric field. The materials are 0.859 Pb(Mg1/3Nb2/3)O3–0.141 PbTiO3 doped with 2.5% SrTiO3 or BaTiO3. Dielectric properties are determined as functions of temperature and electric field. The equivalent piezoelectric coefficients were found as functions of temperature to be equal to or superior to the lead zirconate–titanate ceramics at very modest dc bias fields (2 kV/cm) at temperatures in the range from 10 to 35 °C. Outside of this temperature range, the piezoelectric and dielectric coefficents decrease rapidly. Electromechanical losses were found to be sufficiently small for the SrTiO3 composition but not the BaTiO3 composition.

Finite-element modeling of lead magnesium niobate electrostrictive materials: Dynamic analysis

“…1 The current need for high power in sonar applications leads to the emergence of new transduction materials relying upon the magnetostrictive 2 or the electrostrictive effects. 3 In electrostrictive materials, the strain is proportional to the square of the polarization. 4,5 Compared to PZT ceramics, lead magnesium niobate ceramics (Pb͑Mg 1/3 Nb 2/3 ͒O 3 ͒ ͑PMN͒ exhibit two interesting properties: [6][7][8][9] ͑1͒ the hysteresis in the electric field-polarization curve is reduced if the temperature is correctly chosen; and ͑2͒ high strains (⌬l/lϭ0.1%) can be obtained under moderate electric fields.…”

The inclusion and inhomogeneity problems of electrostrictive materials with periodic microstructure

“…However, unlike piezoelectric materials, the relationship between electric fields and elastic strains in electrostrictive materials, such as lead magnesium niobate (PMN), is nonlinear with no hysteresis, even if the applied electric field is relatively low (Newnham, 1991;Damjanovic and Newnham, 1992). Electrostrictive transducers have already been used in a number of applications, including ultrasonic motors (Uchino, 1986), medical probes (Takeuchi et al, 1989), adaptive optical systems (Galvagni, 1990), underwater transducers (Rittenmyer, 1994), and more recently micro-electro-mechanical systems (MEMS); see Uchino (1997) for a detailed discussion.…”

Electrical response of piezoelectric materials under mechanical excitation

“…The problem of investigating mechanical and electrical disturbances in piezoelectric transducers in the form of a plate and of a bar under various time-dependent input conditions is of great importance in acoustics, especially in the detection of ultrasonic waves and in underwater signaling. 6,7 Researchers 8-10 have studied the electrical response emitted by such transducers due to shock-loaded stress and found the response to be of a transient nature.…”