报导了硬脂酸凝胶法制备的 Ba Ti O3纳米晶及烧制的陶瓷材料的特殊物性。用 X射线衍射、高分辨透射电镜、X荧光光谱、表面光电子能谱、介电谱、热释电谱研究了纳米微粉及陶瓷材料的晶体结构、晶粒尺寸、体相和表面相组份及铁电性能。结...报导了硬脂酸凝胶法制备的 Ba Ti O3纳米晶及烧制的陶瓷材料的特殊物性。用 X射线衍射、高分辨透射电镜、X荧光光谱、表面光电子能谱、介电谱、热释电谱研究了纳米微粉及陶瓷材料的晶体结构、晶粒尺寸、体相和表面相组份及铁电性能。结果表明 ,所有样品在室温下均为立方结构 ,没有铁电性 ,陶瓷样品在低温下 ( <2 0 0 K)具有铁电性。并发现纳米晶 Ba Ti O3及陶瓷具有湿敏特性。展开更多
The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very d...The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very different from those in a quantum dot. In a QDQW, the donor energy levels depend on not only the radius of core and the barrier, but also the numbers of small wells. When there exist two small wells outside the core, the “band gap”exists between donor levels, and its width depends on the depth of the small wells.展开更多
Cluster model with DV-Xαmethod is used to study the structural and electronic properties of the p-type doping of ZnSe.It is found that there is Jahn-Teller distortion for P doping and almost no Jahn-Teller distortion...Cluster model with DV-Xαmethod is used to study the structural and electronic properties of the p-type doping of ZnSe.It is found that there is Jahn-Teller distortion for P doping and almost no Jahn-Teller distortion for N doping,and that the impurity levels with respect to the maximum of valence band are 118 and 96meV for N and P doping,respectively.The reasons why N can serve as a better dopant than P for p-type ZnSe are discussed.展开更多
文摘报导了硬脂酸凝胶法制备的 Ba Ti O3纳米晶及烧制的陶瓷材料的特殊物性。用 X射线衍射、高分辨透射电镜、X荧光光谱、表面光电子能谱、介电谱、热释电谱研究了纳米微粉及陶瓷材料的晶体结构、晶粒尺寸、体相和表面相组份及铁电性能。结果表明 ,所有样品在室温下均为立方结构 ,没有铁电性 ,陶瓷样品在低温下 ( <2 0 0 K)具有铁电性。并发现纳米晶 Ba Ti O3及陶瓷具有湿敏特性。
基金Supported by Natural Science Foundation of China under Grant Nos. 10574077 and 10774085the "863" Programme of China under Grant No. 2006AA03Z0404MOST Programme of China under Grant Nos. 2006AA03Z0404 and 2006CBOL0601
文摘我们理论上学习准确 diagonalization 方法与纺纱轨道相互作用(SOI ) 在联合的量点的 InAs 平行(CQD ) 限制的二交往电子的旋转性质。通过汗衫和三位字节混合的导致的纺纱说的 SOI，我们为弱、强壮的 SOI 显示出不同旋转性质。我们在 SOI 下面调查二个电子的协调汗衫三位字节旋转摆动，并且表明取决于 SOI 力量，内部点的分离和外部磁场的旋转摆动的详细行为。为了更好理解旋转动力学的内在的物理，我们为弱、强壮的 SOI 介绍四水平的模型 Hamiltonian，并且发现 SOI 在飞机导致了，有效磁场能是从二电子的刺激精力系列提取的份量上。
基金the Doctoral Fund of the State Education Commission of China under Grant No.96002703.
文摘The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very different from those in a quantum dot. In a QDQW, the donor energy levels depend on not only the radius of core and the barrier, but also the numbers of small wells. When there exist two small wells outside the core, the “band gap”exists between donor levels, and its width depends on the depth of the small wells.
基金Supported by the'863'High Technology Program of China.
文摘Cluster model with DV-Xαmethod is used to study the structural and electronic properties of the p-type doping of ZnSe.It is found that there is Jahn-Teller distortion for P doping and almost no Jahn-Teller distortion for N doping,and that the impurity levels with respect to the maximum of valence band are 118 and 96meV for N and P doping,respectively.The reasons why N can serve as a better dopant than P for p-type ZnSe are discussed.
