Grain‐Oriented Glass‐Ceramics for Piezoelectric Devices

Abstract

Grain-oriented glass-ceramics of LizSizOs, fresnoite (BazTiSizOs), and its isomorphs Sr2TiSi208 and BazTiGe2Os, were prepared by recrystallizing glasses in a temperature gradient. Electromechanical and hydrostatic piezoelectric properties of these glass-ceramics were measured. Piezoelectric voltage coefficients g , and hydrostatic voltage coefficient gh of these glass-ceramics are comparable to those of polyvinylidene fluoride and an order of magnitude higher than the corresponding values of lead zirconate-titanate. These glass-ceramics seem to be attractive candidate materials for hydrophones and several piezoelectric devices. Hydrostatic piezoelectric properties of BazTiSizOs and BazTiGeZO8 single crystals were also measured. The unusually high values of gh in fresnoite single crystals and glass-ceramics are supposed to be due to positive d3, in these materials. A composite model is proposed to explain the positive sign of d3, in fresnoite based on its crystal structure and internal Poisson's ratio stress.

Correlation between the temperature of molten state and the SH intensity of 30BaO 15TiO2 55GeO2 crystallized glass

“…The correlation between the refractive index of the mother glass and the SHG of crystallized glass can be explained by an alternative interpretation from the viewpoint of refractive index and the pyroelectricity. Since fresnoite Ba2TiGe2O8 was reported as pyroelectric material, 7) the refractive index is expected to depend on the polarization of the matrix. If SHG of a crystallized glass is correlated to the refractive index of the mother glass, it can be a guide for making the crystallized glass with large optical nonlinearity, even if the origin of the increase of refractive index is not well clarified.…”

“…Since the crystallization of the precursor glass adds such extrinsic properties as optical nonlinearity 1)-5) or piezoelectricity, 6)- 7) various properties of crystallized glass promise a large capacity to fabricate novel functional devices built in a glass material. Ba2TiGe2O8 8)-9) is one of the fresnoite-type (Ba2TiSi2O8) phases 10) with the Ti cation taking up a square pyramid (TiO5) structure and the spontaneous polarization along the c-axis.…”

“…Halliyal et al have reported the physical properties of both Ba2TiGe2O8 crystallized glass (glass-ceramic) and a Ba2TiGe2O8 single-crystal and showed that the piezoelectricity of crystallized glass is comparable to that of a Ba2TiGe2O8 tetragonal singlecrystal. 6), 7) Recently, focusing on the second-order optical nonlinearity of Ba2TiGe2O8 crystallized glass, our group has reported a large second order optical nonlinearity, d33 = 24 ± 3 pm/V, observed in a surface crystallized 30BaO·15TiO2·55GeO2 (BTG55) glass. 3) Because the optical nonlinearity of the BTG55 crystallized glass was larger than that of a Ba2TiGe2O8 single crystal, crystallized glass containing nonlinear optical crystals has great potential for nonlinear optical devices.…”

Spectral analysis of Pr3+-, Sm3+- and Dy3+-doped transparent GeO2–BaO–TiO2 glass ceramics

“…Ba 2 TiGe 2 O 8 is known to show ferroelastic, pyroelectric and piezoelectric properties [4][5][6]. Because of such attractive properties, grain-oriented crystallized glasses (nontransparent) consisting of Ba 2 TiGe 2 O 8 have been fabricated by several authors and, in particular, their pyroelectric properties have been examined [6][7][8][9]. Fabrication of transparent crystallized glasses with Ba 2 TiGe 2 O 8 crystal and studies on their optical non-linearity are also well presented in literature [2,10].…”

Orientated crystallization of fresnoite glass-ceramics by using a thermal gradient

“…3,4 Since the possibility of making a polar glassceramics by the crystallization of a glass has been demonstrated successfully, many additional investigations have been done because of some fabrication advantages.…”