The Research Of Doping And Liquid Coating Modification Of BZT Based Capacitance Dielectric Material

As an important ferroelectric material, Barium zirconate titanate?BZT?, with its excellently dielectric and ferroelectric characteristics, is always applied to various components. In order to improve its dielectric properties and temperature stability, doping and coating are usually used to modify BZT material for the sake of achieving the needs of practical applications.BaZr_0.1Ti_0.9O₃ based ceramics powder modified with Fe₂O₃, Gd₂O₃, La₂O₃ and Sm₂O₃ were prepared by the solid reaction method, and then the ceramics powder was coated with a layer of Al2O₃, SiO₂ using a wet coating method. Then the microstructure and the dielectric properties of the samples are analyzed. The research results are listed as follows:With the increasing of the amount of Fe₂O₃, the ?r increases and then decreases. ?r reaches to a higher value when y=1.00, with tan? decreasing. With the increasing of the amount of Gd₂O₃, the ?r reaches to a higher value when y=0.20 and 0.60, the tan? decreases in general. Doping exhibits a peak shifting and peak pressure effect.With the increasing of the amount of La₂O₃, ?r increases under the condition of room temperature, the tan? was decreases. When doping of La₂O₃, Curie peak of the samples increases, accordingly, with obviously shifting peak and faintly broadening effect. When Sm₂O₃ is co-doped, the ?r increases and then decreases, the tan? was increases. Doping of Sm₂O₃ has a peak shifting and peak pressure effect.With the increasing of amount of Al₂O₃, the ?V and ?r gradually reduces, while the tan? increases. The Curie peak moved to a lower temperature and peak pressured under A?B technological conditions.With the increasing of amount of Si O₂, the ?V and ?r gradually reduced, while the tan? increased. The Curie peak moved to a higer temperature under A?B technological conditions. Under B conditions, the influence made by coating on peaks pressure is insignificant.