Tatsuya Okano

A Ternary System PbO-TiO2-ZrO2

In a ternary system PbO--TiO2-- ZrO2, specimens of various compositions are prepared by solid state reactions and analyzed by x-ray- diffraction method. A reaction diagram of this system is proposed. Some compounds ZrTiO4, PbTiO3, PbZrO3 and solid solutions Pb(Ti-- Zr)O3 were early known, and no other compounds are found here. Single phases of perovskite-type structure extend over wider ranges around Pb(Ti- Zr)O3 than expected. Some ceramic specimens among them belonging to these phases are examined as to their dielectric and piezoelectric properties.

Piezoelectric Ceramics of Pb(Zr–Ti)O3 Modified by A1+B5+O3 or A3+B3+O3

The properties of the solid solutions (Pb1-x–Ax)((Zry–Ti1-y)1-x–Bx)O3 or (1-x)Pb(Zry–Ti1-y)O3–xABO3 are studied, where A is a mono- or trivalent ion and B a penta- or trivalent ion as follows: A1+=K, Na, B5+=Sb, Nb, Bi; A3+=Bi, La, B3+=Fe, Al, Cr. The composition ranges examined are mostly within x<0.2 and 0.4<y<0.7. With the present method of preparation by the solid state reaction, the soluble range lies mostly within about ten mole percent substitution, but in some cases, for example, for the combination of Bi–Fe or Na–Nb, it spreads much wider. The effects of B ion on the falling of the Curie point and on the shift of the boundary between the tetragonal and rhombohedral phases are discussed. The piezoelectric performances of Pb(Zr–Ti)O3 ceramics are improved by the present modification with ABO3; that is, the dielectric constant increases and the electromechanical coupling coefficient first increases to a broad maximum and then decreases. The coupling coefficient over 0.5 is easily obtained even for less dense ceramics, especially in the case of NaNbO3 substitution.

36.4: 3.4‐inch Full‐Color QHD AMOLED Display using Large‐Size Flexible Substrate with Highly Reliable OS‐FETs

We report a 300mm × 360mm flexible FET substrate made by our transfer technology and 3.4-inch full-color AMOLED display with oxide FET flexible substrate. Our transfer technology has advantages in applicability for a large-size substrate and cost performance because laser irradiation is not needed.