The dielectric response of KDP crystal near phase transition is investigated by an experiment similar to those well-known in the experimental study of polarization reversal.
It was found that the piezoelectric effect of KDP crystal was very important in the interpretation of the observed results. If a careful consideration is made to substract out the effects of the piezoelectric coupling, the observed results may be interpreted as supporting the current view that the origin of the central mode may be a homogeneous exponential decay of polarization fluctuations.
And we succeeded in observing the polarization reversal current below, $T_c$, where we found the switching time was dependent on the applied field strength and the reversal current had no threshold field strength.
상전이 온도 근처에서 KDP 결정의 dielectric 반응을 polarization reversal 실험과 같은 방법으로 연구했다.
얻어진 자료를 분석하는데 KDP의 piezoelectric효과는 중요한 부분을 차지하며, piezoelectric효과를 이론적인 계산으로 제거한다면 central mode의 근원이 polarization fluctuation의 homogeneous exponential decay라는 많은 이론들을 뒷받침한다고 할 수 있겠다.
그리고 $T_c$이하에서 polarization reversal current를 발견하였으며, switching time이 걸어준 전자에 depend하는 것과 reversal current threshold field가 존재하지 않는 것도 발견되었다.
