论文部分内容阅读
用偏光显微镜和扫描电子显微镜观察研究了不同取向BaTiO3铁电单晶在Vickers压痕作用下微裂纹与90。铁电畴变的形态。发现对于[001]取向极化的BaTiO3铁电单晶,压痕诱发短裂纹不仅发生在沿着压痕对角线方向,而且由于相邻等价畴变区界面的结构错配,还发生在与压痕对角线成45°的方向。对于[100]取向的BaTiO3铁电单晶,在偏离水平方向(垂直于极化方向)约15°～20°角出现了对偶长裂纹。如果将压痕的对角线从极化方向旋转45°,则压痕诱发的裂纹长度大大缩短。认为由于结构错配的影响,裂纹倾向于沿着两畴变区的界面或沿着已畴变区和未畴变区的界面形成。
The polarized light microscopy and scanning electron microscopy were used to study the microcracks and the micro-cracks in the Vickers indentation of BaTiO3 ferroelectric crystals with different orientations. Ferroelectric domain morphology. It was found that for the [001] -oriented BaTiO3 ferroelectric single crystals, indentation-induced short cracks not only occur along the diagonal of the indentation, but also occur due to the structural mismatch of adjacent interface of equivalent domains In the direction of 45 ° to the diagonal of the indentation. For [100] oriented BaTiO3 ferroelectric single crystals, even-long cracks appear in the angle of 15 ° ~ 20 ° away from the horizontal direction (perpendicular to the polarization direction). If the diagonal of the indentation is rotated 45 [deg.] From the polarization direction, the indentation-induced crack length is greatly shortened. It is considered that cracks tend to form along the interface between two domains or along the interfaces between domains that have been changed and domains that have not been changed, due to the influence of structural mismatch.