Masakazu Marutake

Composition Dependence of the Phase Transition Temperatures in the Mixed Crystal Systems near SrTiO3

Elastic measurement has been done for single crystals of Sr 1- x Ba x TiO 3 ( x =0, 0.006, 0.012, 0.014) and Sr 0.941 Ca 0.059 TiO 3 in the temperature range from 4 K to 240 K. The structural phase transition temperature T a , where elastic anomaly occurred, was found to decrease with Ba-concentration, while it increased with Ca-concentration. Dielectric constants for the Sr 1- x Ba x TiO 3 system have also been measured with stress-treated crystals.

Search for a Material with Temperature-Independent Piezoelectric Constant d31 in Nb-Modified Pb(Zr, Ti)O3 Ceramics

Investigations were made regarding the temperature characteristics of the piezoelectric constant d31 of Pb(Zr, Ti)O3 ceramics. The composition, Pb1-x/2(Zr0.52Ti0.48)1-xNbxO3, was exclusively used, and the amount of Nb, x, was controlled in detail. The specimen near x=0.012 was found to have a temperature-independent value of d31 over the temperature range between 20°C and 180°C.

Applications and measurements of piezoelectrics—A review of developments in Japan

Abstract The following three special topics have been selected from recent Japanese work: (1) An analysis of the generation of high voltages by impact on piezoelectric ceramics, in which the nonlinear relations between stress and strain are studied; (2) Measurements of piezoelectric loss angles, especially of Rochelle salt crystals in the ferroelectric state, in which reversible domain wall motion proportional to the electric field is emphasized; (3) Piezoelectricity and related effects in high molecular-weight polymers, in which there are examples of piezoelectricity of the 2nd-kind (polarization produced by stress gradient).

Electromechanical Properties of Composite Bending-Type Transducers.

A composite bending-type transducer is proposed for the purpose of measuring the elastic compliance constant of nonpiezoelectric material at rather low frequencies. It consists of two thin plates with different thicknesses, bonded together, of which one is piezoelectric and the other is nonpiezoelectric. We can calculate the elastic compliance constant of the nonpiezoelectric material from the value of the resonance frequency of the transducer obtained from the measurement of its electrical admittance, together with the electromechanical coupling factor and the elastic compliance constant of the piezoelectric driver. In this paper, the resonance frequency of the transducer is calculated in the general case, and the experimental results are shown in some simple cases. The measurements of the elasticity of nonpiezoelectric materials will be reported in the future.

Electrical and Optical Properties of Hot-Pressed Ba(La1/2Nb1/2)O3–PbZrO3–PbTiO3 Ceramics

Hot-pressed ceramics of the solid solution in the ternary systems xBa(La1/2Nb1/2)O3–(1-x)[Pb(ZryTi1-y)O3] show excellent optical and electrooptical characteristics, comparable to PLZT. Linear and quadratic electrooptical coefficients, rc and R, are determined for more than ten specimens of various compositions near the morphotropic phase boundary between the tetragonal and the rhombohedral phases and maximum values of rc=10.73×10-10m/V and R=12.0×10-16 m2/V2 are observed. Dielectric and electromechanical measurements along with X-ray analysis are also carried out to determine the phase diagram.

Electromechanical Properties of the Ferroelectric Crystal NaH3(SeO3)2 near the Curie Point

Elastic compliance constants (at constant electric field) s 11 E , s 22 E and s 33 E and electromechanical couplins factors k 12 and k 13 have been measured in NaH 3 (SeO 3 ) 2 near the Curie point, -79°C. A new theory, which takes account of elastic nonlinearity or the third elastic constants, is proposed to explain the change of s D (at constant electric displacement) below the Curie point. This theory is valid for most of the elastic anomalies in ferroelectric crystals.

Phase transitions in lanthanum modified lead-barium metaniobate (PBLN)

Abstract Lattice constants of (Pb1-y Ba y )1-x La x Nb2-x/5O6 have been measured by means of x-ray powder analysis over the range of x=0–0.1 and y=0.4, and the comparison with dielectric measurements for ceramics reveals the existence of the successive transitions between the tetragonal (para), the tetragonal (ferro) and the orthorhombic (ferro) phase. It is also pointed out that the optical anisotropy is likely to depend on the deformations of the octahedra of oxygens.

Progress in the Phenomenological Theory of Piezoelectricity in the Ferroelectric Materials

A history of piezoelectric materials is reviewed in retrospect since the discovery of Rochelle salt, and a phenomenological theory is reviewed of the ferroelectricity on which the piezoelectricity is based. A distinction between the isothermal and the adiabatic process, a pseudoproper ferroelectric transition and an elastic anomaly are described. It is proposed that (1) the spontaneous polarization is not necesarily restricted to that of the soft mode and (2) the nonlinear terms determining the spontaneous values should be considered, not only for the quantity which is responsible for the ferroelectric transition but also for those that couple with the former in Muellers theory.

Optical and electrical properties of La-modified (Pb−Ba)Nb2O6 ferroelectric ceramics

Optical and electrical properties, together with phase transitions, were investigated for thc lanthanum-modificd lead-barium metaniobate (Pb1-yBay)1-xLaxNb2-x/5O6. Hot-pressed ceramics with compositions near the orthorhombic-tetragonal morphotropic phase boundary were found to have excellent optical characteristics and high piezoelectricity.

Electrooptical Properties of the Ferroelectric Ceramics of the Solid Solution Sr(La1/2Nb1/2)O3–PbZrO3–PbTiO3

Investigations were made regarding the optical and electrooptical properties for some compositions of the system Sr(La1/2Nb1/2)O3–PbZrO3–PbTiO3. Birefringences and half-wave voltages were measured as a function of temperature and biasing electric field. A figure of merit was determined and light modulation characteristics were, also, briefly examined. Results were compared with those of electrooptical crystals, such as KH2PO4, BNN and SBN.