ba1xbixti1ymnyo3和bi5xlaxti3fe1ycoyo15多铁陶瓷的磁性 铁电性以及介电性的分析word格式论文.docx

优秀毕业论文 精品参考文献资料 the samples show relaxor ferroelectric behavior. As the increasing of Mn content, the dielectric peak move to high temperature, the dielectric loss is increased. All the samples show ferroelectric properties; as for the 0.07 and 0.1 Bi content, as the Mn content increasing from 0 to 0.02, the coercive force and remnant polarization is decreased, as the Mn content further increasing, the coercive force and remnant polarization increase monotonously. We believe that all the experiment results are result from both the structure distortion and the concentration of oxygen vacancies which induced by Bi and Mn dopant. The nominal composition of Bi5-xLaxTi3Fe0.5Co0.5O15(0≤x≤0.4) ceramics were synthesized by sol-gel method. And then effects of sintering temperature and doping content on the magnetism have been studied. As for the samples without La doped, the Bi5Ti3Fe0.5Co0.5O15 ceramics sintered at all the temperature show weak ferromagnetic property at room temperature; As the sintering temperature increased, the M-T curves measure at 1000 Oe under ZFC process have more than one cross point with the FC processed one; The room temperature ferromagnetic property are enhanced by La doping, and no abnormal ZFC and FC appear. It is believe that the abnormal phenomena is caused by the competition of two mechanism, from the following research, the two mechanism is single-ion magnetocrystalline anisotropy and antisymmetric Dzyaloshinsky-Moriya interactions, respectively. The effects of sintering temperature and doping content on the magnetism in Bi5-xLaxTi3Fe0.5Co0.5O15(0≤x≤0.4) ceramics have been studied. The dielectric constant and loss are monotonously decreased as the frequency increase in all the samples; the dielectric properties are weaken by the increasing sintering temperature, the coercive force and remnant polarization increase at first and then decrease; La doping enhanced the dielectric properties, As for the sample sintered at 850 °C, the remnant