论文标题
在外部施加的电场和应变的效果下，tix $ _2 $ _2 $（x = s，se和te）的3x3超级电池的磁性和光学特性计算
Ab-initio calculations of magnetic and optical properties of 3x3 supercell of TiX$_2$ (X = S, Se and Te) compounds under the effect of externally applied electric field and strain
论文作者
论文摘要
二甲烷基化化合物的磁性和光学性能，TIX $ _2 $（X = S，SE和TE）已通过使用密度功能理论（DFT）在Siesta代码中实现的第一原理计算来计算。在这项研究中采用了3x3超级细胞，以便能够从这些化合物的晶胞中获得的性质调整。用磁态（铁磁性质）作为所达到的基态，进行自旋极化计算以获得上述特性。此外，随着自旋极化的生效，采用外部电场（沿z方向）和双轴应变（沿x和y方向）来研究它们对这些特性的影响。还研究了双轴应变对化合物几何形状的影响。可以观察到，化合物的原始超级细胞具有大量的磁矩，并且可以使用施加的场和应变来调节这一点。对于光学性质，使用沿z方向（C轴）的极化光。这些特性包括计算介电功能的实际和虚部，吸收系数，反射率，光导率和0-25 EV能量范围的折射率。观察到这些特性的各种调制，包括在可见区域中具有最高峰的蓝班和红移，以及将能量转移到电磁谱的其他区域。因此，使用可调的磁性和多样的光学性能，这些化合物在旋转型和制造各种光学设备的领域中可能很有用。
The magnetic and optical properties of titanium dichalcogenide compounds, TiX$_2$ (X = S, Se and Te) have been calculated by first principles calculations using density functional theory (DFT) as implemented in SIESTA code. A 3x3 supercell of the compounds is taken in this study to be able to tune the properties obtained from the unit cell of these compounds. With magnetic states (ferromagnetic nature) as the attained ground state, spin polarized calculations are performed to obtain the mentioned properties. Further, with spin polarization into effect, external electric field (along z-direction) and biaxial strain (along x and y-directions) is employed to study their effect on these properties. The effect of biaxial strain on the geometry of the compounds is also studied. It is observed that the pristine supercell of the compounds possess a good amount of magnetic moment and this can be modulated using the applied field and strain. For the optical properties, polarized light along the z-direction (c axis) is used. These properties include the calculation of real & imaginary parts of dielectric function, absorption coefficient, reflectance, optical conductivity and refractive index in 0-25 eV energy range. Various modulations of these properties are observed including the blue-shifts and red-shifts of energies with highest peaks in the visible region and also shifting of energies to other regions of the electromagnetic spectrum. Hence, with the tunable magnetic and diverse optical properties, the compounds can be useful in the field of spintronics and in making various optical devices.
