Abstract: A crystallographically-oriented ceramic containing Pb and in which piezoelectric/electrostrictive properties can be enhanced. Using a raw material having Pb(Zr1-xTiX)O3 as a main component, a ceramic sheet was formed with a thickness of 15 ?m or less. In this material, grains were allowed to grow into an anisotropic shape, and crystal grains with specific crystal planes being aligned were produced. A non-oriented raw material having Pb(Zr1-xTiX)O3 as a main component and the crystal grains were mixed, and shaping was performed so that crystal grains were oriented in a predetermined direction. The shaped body was fired. In the resulting ceramic, the degree of orientation was high at 50% or more. It is possible to enhance the degree of orientation using, as crystal nuclei, a ceramic sheet which can have the same composition as that of the crystallographically-oriented ceramic. Therefore, production can be performed without adding an unnecessary element, for example, for orienting crystals.

Abstract: A (Li, Na, K)(Nb, Ta)O3 based piezoelectric/electrostrictive porcelain composition obtained by adding a slight amount of a Mn compound to a perovskite type oxide containing Li, Na and K as A-site elements and contains at least Nb out of Nb and Ta as B-site elements, where a ratio of a total number of atoms of the A-site elements to a total number of atoms of the B-site elements is not smaller than 1. A composition of the perovskite type oxide as a principal component is represented by a general formula: {Liy(Na1-xKx)1-y}a(Nb1-zTaz)O3. The A/B ratio “a” preferably satisfies 1<a?1.05. The Mn compound as an accessory component is desirably added such that the added amount is not more than 3 parts by mol in terms of Mn atom with respect to 100 parts by mol of said perovskite type oxide.

Abstract: A monomorph type piezoelectric/electrostrictive device includes a piezoelectric/electrostrictive body, which is composed of a non-lead based piezoelectric/electrostrictive crystalline body containing at least Nb, Ta, and one or more types of alkali metal element, which has a cubic crystal structure at a temperature higher than the phase transition point and at least any one of tetragonal and orthorhombic crystal structures at a temperature lower than the phase transition point, and which is curved to a large extent by a polarization treatment to take on a curved shape at a temperature lower than the phase transition point without application of a voltage after the polarization treatment. In the polarization treatment, an electric field is increased at a speed of from 0.1 (kV/mm)/sec or more to 5 (kV/mm)/sec or less, with applying the maximum electric field of from 2 kV/mm or more to 1.0 kV/mm or less.

Abstract: There is disclosed a piezoelectric/electrostrictive device which exhibits an excellent piezoelectric characteristic and which has an only small dependence on a temperature so that the piezoelectric characteristic does not easily change with the temperature. A piezoelectric/electrostrictive device includes a piezoelectric/electrostrictive portion made of a piezoelectric ceramic, and electrodes electrically connected to the piezoelectric/electrostrictive portion. The piezoelectric ceramic can reversibly transit to a tetragonal phase and an orthorhombic phase at a phase transition point as a boundary, and the piezoelectric/electrostrictive portion is formed by a polarization treatment performed on conditions that a treatment temperature ranges from a temperature which exceeds the phase transition point of the piezoelectric ceramic to a temperature which is 50° C. higher than the temperature.