Influence of Si co-doping on magnetic, electrical and optical properties of Ga_(1-x)Mn_xN film grown by MOCVD

A detailed study is presented on magnetic, electrical and optical properties of Ga 1-x Mn x N: Si film grown by metal organic chemical vapor deposition (MOCVD) with high-purity SiH 4 as the Si dopant source. The room-temperature field dependence magnetization and zero-field-cooled (ZFC)/field-cooled (FC) measurements indicate that the film remains room-temperature ferromagnetism and it declines slightly after Si co-doping. However, room-temperature Hall measurements indicate that the electrical property of ...     

Percolation transport and magnetic transitions in a phase-separated manganite La_(0.55)Ca_(0.45)MnO_3

The structural,electronic and magnetic properties of La0.55Ca0.45MnO3 were measured.A rapid change of lattice parameters appeared around 190 K associated with the d z2 orbital ordering and charge ordering (CO) states that were reflected by both magnetization and resistivity.Great difference of magnetizations between the field-cooling (FC) and zero-field-cooling (ZFC) modes below the charge ordering temperature TCO in high magnetic field (H > 4 T) was clearly seen.A field of 5 T (threshold field) is sufficie...     

Production of thick-walled hollow glass microspheres for inertial confinement fusion targets by sol-gel technology

To fabricate thick-walled hollow glass microspheres(HGMs)for inertial confinement fusion(ICF)targets by sol-gel technology,we investigated the effects of glass composition,blowing agent,refining temperature,pressure and composition of furnace atmosphere on the wall thickness of HGMs by numerical simulation and experiments.The results showed that the residence times of the thick-walled HGMs in the encapsulating and refining phases decreased with the increase of wall thickness of HGMs.As a response to this ch...     

Scanning transmission ion microscopy on Fudan SPM facility

In this paper,we report a novel measurement system based on the development of Fudan Scanning Proton Microscopy(SPM) facility.By using Si-PIN diode(Hamamatsu S1223-01) detector,scanning transmission ion microscopy(STIM) measurement system has been set up.It can provide density and structural images with high probing efficiency and non-destruction by utilizing the energy loss of high energy(MeV) and focused ions penetrating through a thin sample.STIM measurement is able to map the density distribution of organic elements which mostly compose biology materials,such information can not be detected by using conventional Be-windowed Si(Li) X-ray detector in Particle Induced X-ray Emission(PIXE) technique.The spatial resolution capability of STIM is higher than PIXE technique at same accelerator status.As a result of STIM measurement,Paramecium attached on the top of Kapton tube was measured by STIM.     

Influence of solar wind dynamic pressure on geomagnetic Dst index during various magnetic storms

The Dst index,designed as a proxy of ring current intensity,is known to be also affected by other magnetospheric current systems,e.g.magnetopause current.The pressure-corrected Dst index is obtained by removing the effects of the solar wind dynamic pressure and the quiet time ring current.However,all previous studies treated the correction coefficient as an averaged parameter for storms of different intensity.In this paper,based on the Burton's equations and employing two independent methods,we will show a ...     

Cleaning method of InSb [111] B of n-InSb [111] A/B for the growth of epitaxial layers by liquid phase epitaxy

The crystal structure of InSb[111]A/B surfaces shows that this structure is polarized.This means that the surfaces of InSb[111]A and InSb[111]B contain two different crystallized directions and they have different physical and chemical properties.Experiments were carried out on the InSb[111]A/B surfaces,showing that tartaric acid etchant could create a very smooth surface on the InSb[111]B without any traces of oxides and etch pit but simultaneously create etch pit on InSb[111]A surfaces.After lapping and polishing,some particles remained on the InSb[111]B surface,they could not be removed easily by standard cleaning process and if these particles remain on the surface of the substrate,the growth layer was not uniform and some island-like regions were observed.The purpose of this work is to remove these particles on the InSb[111]B surface.Some morphology images of both surfaces,InSb[111]A/B,will be presented.     

双酚A双肉桂酸酯光控取向膜

利用双酚A双肉桂酸酯光敏单体在线偏振紫外光作用下发生光交联反应,制备了光控取向膜。制备过程更为简单,不需要高温热处理过程。液晶分子的排列方向与入射紫外光偏振方向垂直。通过紫外光谱和红外光谱分析了光化学反应过程,链聚合反应与异构反应相比,链状聚合反应对于液晶的排列起重要作用。利用偏振红外光谱对取向膜的有序度值计算发现,有序值较小。利用Cano盒测试了方位锚定能的大小为1.28×10-6J/m2。取向膜的热稳定性可以达到90℃。     

电子束直写制作低效取样光栅

低效取样光栅是激光取样技术的一种重要元件 ,它可以看成离轴的二相位的菲涅耳波带板。基于菲涅耳波带板的形成原理 ,对取样光栅的变周期环带结构进行了理论分析 ,推导出取样光栅的透过率函数。并在此基础上 ,采用电子束直写加工光栅掩模 ,制作取样光栅。该方法与一般的光学全息方法相比 ,具有设计灵活、重复性好、适于大批量生产等优点。     

偏晶向(111)硅片闪耀光栅的设计

利用硅单晶的特殊结构可以设计出不同角度的闪耀光栅，再使用MEMS的紫外光刻、各向异性腐蚀等常规工艺就可以完成硅闪耀光栅的制作。设计了一种利用偏转晶向(111)硅片制作小角度闪耀光栅的方法，避免了利用其它晶向的硅片制作闪耀光栅的缺点。利用这种方法制作了线宽为4μm的硅闪耀光栅，使用原子力显微镜(AFM)进行了光栅表面形貌测试，得到平均表面粗糙度为110．94nm，试验结果表明制作的硅光栅样片具有良好光学特性的反射表面和光栅槽形。