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在恒温条件下应用数字积分电荷测量方法研究了压电陶瓷中异极性电荷引起的长时间压电弛豫效应。实验判明了同极性和异极性电荷在陶瓷中有不同方式的体积分布,在热电效应和压电效应中其贡献的极性与聚合物驻极体相同。只发现了异极性电荷引起的压电弛豫效应,同极性电荷对压电弛豫无贡献。唯象理论给出的随机弛豫规律ΔQ=(1-R_e~(-A_t))ΔQ_∞及自由弛豫规律ΔQ=(1-r_e~(-a_t~(1/2))×ΔQ_∞都分别得到实验证实。由铁电体中的退极化电场可以解释同极性电荷具有体分布的原因。
Under the condition of constant temperature, the digital integral charge measurement method is used to study the long-time piezoelectric relaxation effect caused by the charge of different polarity in piezoelectric ceramics. Experiments show that the same polarities and different polarities have different volumetric distributions in ceramics, and their contributions are the same as that of the polymer electrets in the thermoelectric and piezoelectric effects. Only the piezoelectric relaxation effect caused by the charge of the opposite polarity was found, and the charge of the same polarity did not contribute to the piezoelectric relaxation. The phenomenological theory gives the random relaxation law ΔQ = (1-R_e ~ (-A_t)) ΔQ_∞ and the free relaxation law ΔQ = (1-r_e ~ (-a_t ~ (1/2)) × ΔQ_∞ The experimental results show that the depolarizing electric field in the ferroelectrics can explain the reason why the charge of the same polarity has a bulk distribution.