Advanced Characterization Method

The ferroelectricity of the Poly(vinylidene fluoride-trifluoroethylene-chlorofloroethylene) terpolymer films fabricated by the Langmuir–Blodgett (LB) technology were investigated from 180 to 300 K. The temperature dependence of the remanent polarization and the dielectric response shows a broad peak at ~ 270 K, suggesting a ferroelectric phase transition. Contrary to the perovskite relaxor, a deviation from the Merz’s law is observed in the relation between the coercive field and frequency for the relaxor terpolymer. The particular ferroelectricity of the relaxor terpolymer is considered to be associated with the distinct structure and the dynamics of its typical molecular conformations. ISAF-P1A-15 ___________________________________________________________________________________________________________________ Effect of grain size on the microwave dielectric properties of βBZN ceramics Gao-qun Zhang 1 , Hong Wang 1 , Di Zhou 1 , Jing Guo 1 1 Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education, Xi’an Jiaotong University, Xi’an 710049, China Email: [email protected] In this study, β-BZN ceramics were prepared by the traditional solid state method. The samples sintered at 930 o C for 2 h possessed a relative permittivity of 74 and a Q×f value of 3740 GHz. The grain size of β-BZN ceramics was regulated by changing sintering temperature and heat preservation time. When the sintering temperature was increased from 780 o C to 990 o C, the grain grew from 0.7 um to 1.9 um as approximate exponential function. Grain growth mechanism of β-BZN ceramic with sintering temperature was discussed. The function     3 1000 3 ln 1000 3 T p l t e   about the relationship between the grain size of β-BZN and sintering temperature was obtained by simulation, whose results were in accord with experimental values. For the samples at different heat preservation time, there was deviation between experimental values and results from theory model formula