摘要
The dielectric ceramic of barium dititanate compound BaTi_(2)O_(5) had been prepared through the hydrothermal process by applying different parameters,such as pH-value,reaction time,temperature and pressure.The prepared powders were examined by X-ray diffraction(XRD).The predominant phase was a monoclinic phase with lattice constants(a=16:6381,b=3:555,c=9:3406Å),(β=107:47°,α=γ=90°),and the unit cell volume(527Å^(3)).The surface morphology was demonstrated by Scanning Electron Microscopy(SEM).It exhibited the grains in spherical and elliptical shapes with high homogeneity.The shapes of nanostructure were analyzed by Transmission Electron Microscopy(TEM).The appearance of nanostructures like the nanoparticles and nano rods were found.The size of nanoparticles was in the range of 9–31 nm,and size of nanorods was 32–37 nm.The dielectric measurements were done by using LCR meter at different temperature and frequencies(10,50 and 100 kHz).It was clear that the Curie temperature had a high value up to(485℃).The relative permittivity was partially changed for two prepared samples regarding high pressure and long reaction time,which were the main preparation conditions of hydrothermal method.
