Ferroelectric phase transitions in materials embedded in porous media

Large quantities of highly dispersed ferroelectric objects were obtained by impregnation of two porous dielectric matrixes (porous glass and artificia l opal) with molten ferroelectric materials (NaNO2, KH2PO4 (KDP)). The diam eters of ferroelectric nanoparticles may be varied from about 100 nm to 3-4 nm. The neutron scattering measurements for NaNO2 particles and low freque ncy dielectric permittivity measurements for NaNO2, KDP and Rochelle salt p articles were performed on such nanosize particles systems. The significant shift of transition temperature from the bulk value for KDP particles as t he transition broadening for NaNO2 and KDP particles was observed. (C) 1999 Acta Metallurgica Inc.