Preparation and properties of BaTiSi2O7 glass-ceramics

New lead-free dielectric materials attract great attention for their excellent environment amiability. Pyramid [TiO5] groups existing in BaTiSi2O7 and fresnoite were the characteristic of dielectric materials with spontaneous polarization. However, it was difficult to prepare BaTiSi2O7 ceramics because the phase was unstable below the temperature of 655 degreesC. In this paper, the glass-ceramics with BaTiSi2O7 phase were prepared in a controlled crystallization process, and its dielectric permittivity was measured. With FTIR and XRD, the characteristics of the glass-ceramics were studied. Through the calculation on the lattice deformation in the two types of glass-ceramics, it was concluded that the existence of BaTiSi2O7 in the glass-ceramics was the result of the stress-controlled condition of the remnant glassy matrix. (C) 2003 Elsevier Science B.V. All rights reserved.