Phase separation is linked to many novel behaviors in manganites.[1-4].Recent experiments on spatial confinement of the phase separated manganite films offer new method to study phase separation[3].In this paper,we pr...
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Phase separation is linked to many novel behaviors in manganites.[1-4].Recent experiments on spatial confinement of the phase separated manganite films offer new method to study phase separation[3].In this paper,we present the effect of spatial confinement on the percolative transport
采用第一性原理密度泛函理论结合经典色散修正方法,对固态硝基苯在单轴压缩下的基本结构关系进行了计算。静水压缩和单轴压缩都压缩到初始平衡体积的70%。将静水压下优化后的晶胞体积、晶格参数以及平衡条件下的晶格能与实验值进行了比较,均符合的比较好。同时,为了充分地表征固态硝基苯的各向异性,将硝基苯沿着三个晶格矢量的方向进行单轴压缩,把每个方向的应力张量、能带带隙、每个原子能量的改变分别作为体积压缩比的函数进行了比较和分析。其中,最显著的各向异性效应是在体积压缩比为0.76时,沿X轴压缩导致硝基苯能带带隙闭合,体系呈金属化;而静水压或沿Y轴和Z轴压缩时体系始终呈半导体状态,带隙均大于1.59 e V。为了充分理解这一各向异性特性,我们计算了硝基苯晶体的局域态密度和电荷密度分布,并对金属化现象作出了合理的分析和解释。在不同的压力加载条件下,通过对不同物理量的计算,我们发现X轴方向是硝基苯晶体内部最敏感的方向。这些各向异性效应的研究将有助于人们在原子尺度上深入理解固态硝基苯的物理化学性质。
A series(Sr,Ca)Cu OCl(x=0,0.1,0.3,0.5,0.7,0.9,1)with a LaCu O-type structure were successfully synthesized under high pressure.X-ray powder diffraction pattern show that Ca ion incorporated to the Sr sites *** carri...
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A series(Sr,Ca)Cu OCl(x=0,0.1,0.3,0.5,0.7,0.9,1)with a LaCu O-type structure were successfully synthesized under high pressure.X-ray powder diffraction pattern show that Ca ion incorporated to the Sr sites *** carrier was introduced into materials since Na
The recently discovered Dirac and Weyl semimetals are new members of topological *** from them,topological superconductivity may be achieved,e.g.,by carrier doping or applying *** we report high-pressure resistance an...
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The recently discovered Dirac and Weyl semimetals are new members of topological *** from them,topological superconductivity may be achieved,e.g.,by carrier doping or applying *** we report high-pressure resistance and X-ray diffraction study of the three-
Recently,the ternary metallic compounds MM’X with hexagonal NiIn-type structure have attracted much attention due to their rich magnetic and structural *** resolution neutron diffraction was performed to study the cr...
Recently,the ternary metallic compounds MM’X with hexagonal NiIn-type structure have attracted much attention due to their rich magnetic and structural *** resolution neutron diffraction was performed to study the crystal and magnetic structures as functions of
We investigate doping-and pressure-induced changes in the electronic state of Mn 3d and As4p orbitals in Ⅱ-Ⅱ-V based diluted magnetic semiconductor(Ba,K)(Zn,Mn)Asto shed light into the mechanism of indirect exchange...
We investigate doping-and pressure-induced changes in the electronic state of Mn 3d and As4p orbitals in Ⅱ-Ⅱ-V based diluted magnetic semiconductor(Ba,K)(Zn,Mn)Asto shed light into the mechanism of indirect exchange interactions leading to high ferromagnetic ordering
CaFeAs is special among the 122 materials as due to its reduced unit cell volume and c lattice parameter, which is very close to collapsed tetragonal(CT) phase. So it is very sensitive to external pressure and chemica...
CaFeAs is special among the 122 materials as due to its reduced unit cell volume and c lattice parameter, which is very close to collapsed tetragonal(CT) phase. So it is very sensitive to external pressure and chemical pressure(doping). Optimal Na doped(CaNa)FeAs shows a superconducting transition with T 33 K at ambient pressure. With application of pressure, T decreases nearly linearly with d T c/d P 1.7K/GPa at pressures lower than 2 GPa, and disappears gradually at higher pressure. The disappearance of superconductivity is also companied with the recovery of standard Fermi liquid behaviors of the normal-state transport properties. Moreover,(CaNa)FeAs exhibits a tetragonal(T) to collapsed-tetragonal(c T) transition at about 3 GPa. The evolution of non-Fermi liquid behaviors and superconductivity under pressure are both related to the interband fluctuations.
Strong spin orbital interaction(SOI)can induce unique quantum phenomena such as topological insulators,the Rashba effect,or p-wave *** these three quantum phenomena into a single compound has important scientific *** ...
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Strong spin orbital interaction(SOI)can induce unique quantum phenomena such as topological insulators,the Rashba effect,or p-wave *** these three quantum phenomena into a single compound has important scientific *** we report
Recently,theoretical studies show that layered Hf Te5is at the boundary of weak&strong topological insulator(TI)and might crossover to a Dirac semimetal state by changing lattice *** topological properties of 3D s...
Recently,theoretical studies show that layered Hf Te5is at the boundary of weak&strong topological insulator(TI)and might crossover to a Dirac semimetal state by changing lattice *** topological properties of 3D stacked Hf Te5are expected hence to be sensitive to
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