In the present paper, we study the zero-temperature phase diagram of the doped perovskite manganitesat filling x = 0.5 by the real-space Hartree-Fock approximation method. Our purpose is to resolve a controversialissu...In the present paper, we study the zero-temperature phase diagram of the doped perovskite manganitesat filling x = 0.5 by the real-space Hartree-Fock approximation method. Our purpose is to resolve a controversialissue arising recently on the origin of the charge ordered phases in these systems. We find that the antiferromagneticsuperexchange interaction between the localized spins plays the central role in producing the concerned phases. Ourresults confirm some speculations on this issue.展开更多
研究了PLZT系统中接近铁电和顺电相界的三个反铁电组成在用 Sr 改性后的介电性能和微观结构.实验结果指出,随着 Sr 对 Pb 置换量的增大,材料的介电系数、介质损耗、击穿场强以及介电系数随温度的变化速率均逐渐减小,晶粒度和化学组成的...研究了PLZT系统中接近铁电和顺电相界的三个反铁电组成在用 Sr 改性后的介电性能和微观结构.实验结果指出,随着 Sr 对 Pb 置换量的增大,材料的介电系数、介质损耗、击穿场强以及介电系数随温度的变化速率均逐渐减小,晶粒度和化学组成的均一性则增大.通过研究,获得了介电系数大于2000,Δ∈/∈20在±10%左右的陶瓷材料.文章对此进行了讨论.展开更多
文摘In the present paper, we study the zero-temperature phase diagram of the doped perovskite manganitesat filling x = 0.5 by the real-space Hartree-Fock approximation method. Our purpose is to resolve a controversialissue arising recently on the origin of the charge ordered phases in these systems. We find that the antiferromagneticsuperexchange interaction between the localized spins plays the central role in producing the concerned phases. Ourresults confirm some speculations on this issue.
文摘研究了PLZT系统中接近铁电和顺电相界的三个反铁电组成在用 Sr 改性后的介电性能和微观结构.实验结果指出,随着 Sr 对 Pb 置换量的增大,材料的介电系数、介质损耗、击穿场强以及介电系数随温度的变化速率均逐渐减小,晶粒度和化学组成的均一性则增大.通过研究,获得了介电系数大于2000,Δ∈/∈20在±10%左右的陶瓷材料.文章对此进行了讨论.
