定轴转动带电体的磁场分布

类比定轴转动刚体转动贯量以及电偶极子电场的计算方法得出定轴转动带电体的磁矩及其磁场分布。     

Co-Ni合金薄膜的电化学外延及同步辐射XMCD研究

采用电化学循环伏安法在单晶GaAs(001)衬底上外延沉积了Co-Ni二元合金薄膜. 扫描电子显微镜观察结果显示, 薄膜厚度约180 nm, 其表面由约40 nm大小的颗粒组成. 用X射线荧光法确定了薄膜的组分为Co66Ni34, XRD确定了其为面心立方结构. 用同步辐射圆偏振软X射线分别测量了样品中Co和Ni的吸收谱(XAS), 从而得到X射线磁性圆二色(XMCD)谱, 通过加和定则分别计算出了合金中Co和Ni的轨道磁矩和自旋磁矩, 与纯的Co和Ni样品相比, 它们都有不同程度的增加.     

双铜簇合物的EPR谱、磁性与电子结构研究

本文报导了77K及室温下新合成的双铜簇合物(DMF)₂]·4DMF的EPR及磁性测定结果。所得到的三套EPR谱与磁矩以及S_cc-EHMO量化计算结果综合分析,确认两套谱归属于铜离子上的未配对电子,另一套归属于簇合物三重态电子。固态时顺磁性主要是三重态的贡献,溶液时主要来自铜离子。 该簇合物的电子结构特点:双铜之间有微弱作用。双铜与桥基、端基成键后的剩余价态很少,铜离子上的电子自旋浓度约为单铜化合物的3%,因此铜离子的两套EPR谱强度相当弱。分子轨道前沿的能级接近简并,轨道上的电子形成热激发三重态,造成一套三重态EPR谱。因此,可认为该化合物是一种新型自身磁稀释的三重态双铜簇合物。     

Stern-Gerlach实验的系统研究

结合德国PHYWE公司生产的Stern-Gerlach实验仪,简述了Stern-Gerlach实验的基本原理和内容设计;系统介绍了具体实验装置的组成部件和功能;考虑入射原子束的麦克斯韦速率分布后,理论分析了最终原子沉积束斑的形状;给出了典型的实验测量数据,讨论了测量曲线的偏差来源和进一步设想,评述了这一实验项目教学的意义.     

Magnetizations and magneto-transport properties of Ni-doped PrFe03 thin films

The present study reports the magnetizations and magneto-transport properties of PrFel_xNixO3 thin films grown by pulsed laser ablation technique on LaA103 snbstrates. From DC M/H plots of these films, weak ferromagnetism or ferrimagnetism behaviors are observed. With Ni substitution, reduction in saturation magnetization is also seen. With Ni doping, variations in saturation field （Hs）, coercive field （Hc）, Weiss temperature （0）, and effective magnetic moment （Pelf） are seen. A small change of magnetoresitance with application of higher field is observed. Various essential parameters like density of state （Nf） at Fermi level, Mott＇s characteristic temperature （To）, and activation energy （Ea） in the presence of and in the absence of magnetic field are calculated. The present observed magnetic properties are related to the change of Fe-O bond length （causing an overlap between the oxygen p orbital and iron d orbital） and the deviation of the Fe-O-Fe angle from 180~. Reduction of magnetic domain after Ni doping is also explored to explain the present observed magnetic behavior of the system. The influence of doping on various transport properties in these thin films indicates a distortion in the lattice structure and single particle band width, owing to stress-induced reduction in unit cell volume.     

BnTi(n=1-12)团簇的结构, 电子性质和磁性

利用密度泛函理论广义梯度近似方法得到了BnTi(n=1-12)团簇的基态结构, 并讨论了电子性质和磁性质. 结果表明, n≤5 时, BnTi 基态结构呈平面或准平面, n>5 时, Ti 原子倾向于与较多的B 原子成键而呈三维结构. 由二阶能量差分得出B3Ti, B5Ti, B10Ti 为幻数团簇. Mulliken 布居分析显示BnTi 团簇中电荷由Ti 原子向近邻B 原子转移且以共价键与离子键共存; 除BTi 磁矩为5 μB 外, 其余团簇磁矩处于0-2 μB 之间; 团簇总磁矩主要由Ti 原子的3d 轨道和个别B 原子提供. B3Ti和B7Ti 团簇中, B 原子表现为反铁磁性.     

Chiral structures and tunable magnetic moments in 3d transition metal doped Pt6 clusters

The structural, electronic, and magnetic properties of transition metal doped platinum clusters MPt6 （M=Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn） are systematically studied by using the relativistic all-electron density functional theory with the generalized gradient approximation. Most of the doped clusters show larger binding energies than the pure Pt7 cluster, which indicates that the doping of the transition metal atom can stabilize the pure platinum cluster. The results of the highest occupied molecular orbital （HOMO） lowest unoccupied molecular orbital （LUMO） gaps suggest that the doped clusters can have higher chemical activities than the pure Pt7 cluster. The magnetism calculations demonstrate that the variation range of the magnetic moments of the MPt6 clusters is from 0 μB to 7 μB, revealing that the MPt6 clusters have potential utility in designing new spintronic nanomaterials with tunable magnetic properties.     

Recent progress on isospin breaking corrections and their impact on the muon g－2 value

We describe some recent results on isospin breaking corrections which are of relevance for predictions of the leading order hadronic contribution to the muon anomalous magnetic moment aμ^had.LO when using τ lepton data. When these corrections are applied to the new combined data on the π^±π^0 spectral function, the prediction for aμ^had.LO based on τ lepton data gets closer to the one obtained using e^＋e^- data.     

运动介质的电偶极矩与磁矩

在推导出介质的极化强度与磁化强度的坐标变换公式的基础上,分析导出了运动介质的电偶极矩与磁矩.     

带电粒子在磁镜场中运动时速度的演变

本文从带电粒子在磁镜场中的受力情况入手,求出了带电粒子速度随时间的演化方式,并直接由粒子的洛伦兹方程出发,阐明了磁镜效应,此方法不需要论证粒子的磁矩守恒,从而更简单明了地阐明了磁镜效应.