Boundary influence on the fields and arrangement of the needle domains in barium titanate single crystals
Boundary influence on the fields and arrangement of the needle domains in barium titanate single crystals
复制标题
DOI：
10.1016/j.euromechsol.2021.104322
复制
发表时间：
2021-08
影响因子：
4.1
通讯作者：
Dan Sui;J. Huber;Jie Zhou
中科院分区：
文献类型：
--
作者：
Dan Sui;J. Huber;Jie Zhou
采用叠加理论研究了钛酸钡单晶中针状畴的边值问题，将其分解为一个无限介质解和一个互补解。采用等效刃位错和线电荷模型计算了无限大介质中离散针状畴的场。使用有限元法从线弹性边值问题获得互补解。本文在考虑无牵引边界和平面应力近似下，分析了边界对薄钛酸钡单晶中针状场和排列的影响。根据最小势能原理，发现如果与针尖相关的有效电荷减少到材料的全极化电荷的48%，则可以稳定平行针状畴对。梳状阵列的针域压缩机械载荷下的演变进行了模拟，结果被发现是定性相似的实验观察，以前没有被理论解释。
The superposition theory is adopted to study the boundary value problem of needle domains in barium titanate single crystals, which decomposes into an infinite-medium solution and a complementary solution. The model of an equivalent edge dislocation and line charge is adopted to calculate the fields due to the discrete needle domains in an infinite medium. The complementary solutions are obtained from a linear elastic boundary value problem using the finite element method. The influence of boundaries on the fields and arrangement of the needles in thin barium titanate single crystals is analysed, by considering traction-free boundaries and using the plane stress approximation. According to the principle of minimum potential energy, it is found that pairs of parallel needle domains can be stabilized if the effective charge associated with the needle tips is reduced to 48% of the material’s full polarization charge. The evolution of comb-like arrays of needle domains under compressive mechanical load is simulated, and the results are found to be qualitatively similar to experimental observations which have not previously been explained theoretically.