【摘 要】
:
The intrinsic ferromagnetism of CoBr2 bulk was investigated using DFT(density functional theory)combined with the full potential linear augmented plane wave method and Monte Carlo simulations.The ground state of CoBr2 exhibits ferromagnetic behavior and a
【机 构】
:
Laboratory of Solid Physics,Faculty of Sciences Dhar El Mahraz,Sidi Mohamed Ben Abdellah University,
论文部分内容阅读
The intrinsic ferromagnetism of CoBr2 bulk was investigated using DFT(density functional theory)combined with the full potential linear augmented plane wave method and Monte Carlo simulations.The ground state of CoBr2 exhibits ferromagnetic behavior and a semiconductor character.We used the generalized gradient approximation(GGA)and GGA+U(Hubbard correction)approximations to determinate the magnetic moment.The magnetic moment reached the experimental value and was in good agreement with the other theoretical values.The value obtained was used as an input to a Monte Carlo study to calculate the thermal magnetization and magnetic hysteresis cycles.Ferromagnetic behavior was observed and was found to be due to an positive exchange interaction.These results lead us to believe that this material could be a promising spintronic material.
其他文献
Due to improvements in the sensitivity of gravitational wave(GW)detectors,the detection of GWs originating from the fundamental quasi-normal mode(f-mode)of neutron stars has become possible.The future detection of GWs originating from the f-mode of neutro
在测算零售业综合发展指数基础上,基于Theil指数、探索性空间数据分析研究了 2000-2017年中国零售业发展的时空分异格局,采用空间计量模型分析其驱动因素及空间溢出效应.结果表明,中国零售业发展整体水平逐渐提升,东部地区是零售业发展的主要区域,中、西部地区在零售业发展方面仍相对滞后,始终保持着“东-中-西”阶梯式递减发展格局;零售业发展的区域差异在波动中呈缩小趋势,Theil指数降幅42.38%,组间和组内差异均趋于缩小;零售业发展水平具有显著的空间正相关,“马太效应”显著,地理空间是影响其演变的重要
Based on molecular dynamics simulations,we have studied the wetting behaviors of water on the talc-like surface with different surface polarity by modifying the charge distribution of surface hydroxyl(-OH)groups.With the change of the charge of the hydrog
Nucleation underlies the dynamics of most first-order phase transitions in natural and man-made systems.However,most of the systems of interest are out of equilibrium.Little is known on the effect of nonequilibrium factors on the dynamics of nucleation.He
In this manuscript,the traversable wormhole solutions have been explored in modified f(R,G)gravity by taking into consideration the model f(R,G)=R+γG2,where R is the Ricci curvature scalar and G is the Gauss-Bonnet term.An acceptable form of the redshift
设计了一种新型的p+深层扩散结构p-in-n硅微条核辐射探测器,介绍了该探测器的结构、工艺及性能测试结果.探测器为灵敏面积10 mm×10 mm的单面60条探测器,p+注入条宽64 μm,栅宽96 μm,p+注入条中心下方的p+深层扩散区宽10 μm.测试内容包括该探测器的电学特性(反向漏电流、耗尽电压、条间电容、条间电阻)和探测特性(能量分辨、条间串扰).该探测器在45 V全耗尽偏压下,各条的反向漏电流均小于1.3 nA.探测器对241 Am α粒子的能量分辨率约为2.6%,相邻条之间的串扰率约为4%.
提出采用具有高分辨特性的同步挤压小波时频变换来获得含噪动液面信号的时频分布,从时频平面上识别出动液面信号的时频能量分布并将其截取出来,采用同步挤压重构公式得到滤波后的动液面信号,根据该信号波形出现大幅突变的位置(采样点序号)和采样频率即可确定其出现的时刻点.通过与采用小波变换取得的时频平面相对比,同步挤压小波时频平面的分辨率更高,对动液面信号的识别能力更强,能够有效提取出动液面信号,更准确地获取其开始出现的位置.
利用NCEP/NCAR月平均再分析资料中的500 hPa位势高度数据,基于振幅定义了冬季(12-2月)东亚大槽振幅指数IEAT,分析了东亚大槽与东亚冬季地面气温之间的联系.结果 表明,IEAT能够反映东亚大槽的强度变化.1948-2018年IEAT总体有微弱的增大趋势,表明东亚大槽强度增大.IEAT与东亚沿岸地区的冬季气温呈显著负相关,当IEAT偏大(小)时,东亚沿岸地区冬季气温偏低(高).IEAT偏大的年份,地面西伯利亚高压偏强和850 hPa经向风异常偏大是东亚沿岸地区冬季地面气温异常偏低的主要原因.
Applying the transfer matrix and Green\'s function methods,we study the valley-resolved transport properties of zigzag graphene nanoribbon(ZGNR)junctions.The width of the left and right ZGNRs are NL and NR,and NL≥NR.The step/dip positions of the conduct
某些高层建筑的楼梯间外纵墙,是紧临建筑外部的高度很大的一字型剪力墙,在自身高度范围内,除了底部约束和顶部约束外,其他位置所受约束较弱,存在面外屈曲失稳的风险.建立了描写一字型剪力墙在自重作用下发生面外挠曲变形的微分方程,并求出了其解析解,解的数学形式与贝塞尔函数有关.针对4种边界约束形式(底端固支、顶端自由;底端固支、顶端简支;两端简支;两端固支),高精度地给出了一字型剪力墙发生面外失稳的屈曲临界条件,通过算例对屈曲临界条件的工程应用价值进行了简单评述.