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
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
We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots （CQDs） with spin-orbit interactions （SOI） by exact diagonalization method. Through the SOI...We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots （CQDs） with spin-orbit interactions （SOI） by exact diagonalization method. Through the SOI induced spin mixing of the singlet and the triplet states, we show the different spin properties for the weak and strong SOI. We investigate the coherent singlet-triplet spin oscillations of the two electrons under the SOI, and demonstrate the detailed behaviors of the spin oscillations depending on the SOI strengths, the inter-dot separations and the external magnetic fields. To better understand the underlying physics of the spin dynamics, we introduce a four-level model Hamiltonian for both weak and strong SOI, and find that the SOI induced in plane effective magnetic fields can be quantitatively extracted from the two-electron excitation energy spectra.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 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.
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We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots （CQDs） with spin-orbit interactions （SOI） by exact diagonalization method. Through the SOI induced spin mixing of the singlet and the triplet states, we show the different spin properties for the weak and strong SOI. We investigate the coherent singlet-triplet spin oscillations of the two electrons under the SOI, and demonstrate the detailed behaviors of the spin oscillations depending on the SOI strengths, the inter-dot separations and the external magnetic fields. To better understand the underlying physics of the spin dynamics, we introduce a four-level model Hamiltonian for both weak and strong SOI, and find that the SOI induced in plane effective magnetic fields can be quantitatively extracted from the two-electron excitation energy spectra.
