摘要
Polyvinylidene fluoride （PVF<sub>2</sub>） exhibits at least four crystalline phases （α, β, γ, and δ）. Among them, β phase is the most important one because it is directly related to the piezoand pyro-electric activities of PVF<sub>2</sub>. In recent years, more attention has been paid to the
基金
Project supported by the National Natural Science Foundation of China.
