Rashba-like spin-orbit interaction and spin texture at the KTaO3_\text{3} (001) surface from DFT calculations

Rashba-like spin-orbit interaction at oxide heterostructures emerges as a much sought-after feature in the context of oxide spintronics and spin-orbitronics. KTaO$_3$ (KTO) is one of the best substrates available for the purpose, owing to its strong spin-orbit interaction and alternating $+1|-1$ charged layers along the (001) direction. Employing first-principles calculations within density functional theory (DFT) and proposing a possible electrostatic model for charge transfer to the surfaces of KTO slabs, we comprehensively analyze Rashba-like spin-orbit interaction with the help of three-dimensional band dispersion, isoenergetic contours, and projected spin textures $-$ all directly obtained from our DFT results $-$ in a thin insulating slab and a conducting thick slab of KTO. Our results reveal reasonably strong linear Rashba interaction with no signature of Dresselhaus or higher order Rashba interactions in the systems considered here. The rigorous analysis presented here may be crucial for future developments in oxide spintronics.Comment: 8 pages, 6 figure

Enhanced functionalization of Mn2O3@SiO2 core-shell nanostructures

Core-shell nanostructures of Mn2O3@SiO2, Mn2O3@amino-functionalized silica, Mn2O3@vinyl-functionalized silica, and Mn2O3@allyl-functionalized silica were synthesized using the hydrolysis of the respective organosilane precursor over Mn2O3 nanoparticles dispersed using colloidal solutions of Tergitol and cyclohexane. The synthetic methodology used is an improvement over the commonly used post-grafting or co-condensation method as it ensures a high density of functional groups over the core-shell nanostructures. The high density of functional groups can be useful in immobilization of biomolecules and drugs and thus can be used in targeted drug delivery. The high density of functional groups can be used for extraction of elements present in trace amounts. These functionalized core-shell nanostructures were characterized using TEM, IR, and zeta potential studies. The zeta potential study shows that the hydrolysis of organosilane to form the shell results in more number of functional groups on it as compared to the shell formed using post-grafting method. The amino-functionalized core-shell nanostructures were used for the immobilization of glucose and L-methionine and were characterized by zeta potential studies

The study of Microstructure of III-V Polar on Non-Polar Heterostructures By HRXRD

In this article, we report on the detailed high resolution x-ray diffraction data analysis of three GaAs films deposited by metal organic vapour phase epitaxy on Si substrates. In the GaAs/Si films the effect of anti phase domains is seen by the selective broadening of (002) and (006) reflections. Further as the (006) reflection is a very weak reflection, such films cannot be analyzed by conventional Williamson-Hall plots using (002), (004) and (006) reflections. We find that using (111), (333) and (444) reflections it is possible to use the standard Williamson-Hall analysis and extract parameters related to the microstructure of the films. We have also carried out the analysis to determine the tilt and twist between the mosaic blocks after correcting for the effects of the finite lateral coherence length. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/930

The study of Microstructure of III-V Polar on Non-Polar Heterostructures By HRXRD

In this article, we report on the detailed high resolution x-ray diffraction data analysis of three GaAs films deposited by metal organic vapour phase epitaxy on Si substrates. In the GaAs/Si films the effect of anti phase domains is seen by the selective broadening of (002) and (006) reflections. Further as the (006) reflection is a very weak reflection, such films cannot be analyzed by conventional Williamson-Hall plots using (002), (004) and (006) reflections. We find that using (111), (333) and (444) reflections it is possible to use the standard Williamson-Hall analysis and extract parameters related to the microstructure of the films. We have also carried out the analysis to determine the tilt and twist between the mosaic blocks after correcting for the effects of the finite lateral coherence length. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/930

Anomalous Raman scattering from phonons and electrons of superconducting FeSe0.82_{0.82}

We report interesting anomalies in the temperature dependent Raman spectra of FeSe$_{0.82}$ measured from 3K to 300K in the spectral range from 60 to 1800 cm$^{-1}$ and determine their origin using complementary first-principles density functional calculations. A phonon mode near 100 cm$^{-1}$ exhibits a sharp increase by $\sim$ 5% in frequency below a temperature T$_s$ ($\sim$ 100 K) attributed to strong spin-phonon coupling and onset of short-range antiferromagnetic order. In addition, two high frequency modes are observed at 1350 cm$^{-1}$ and 1600 cm$^{-1}$, attributed to electronic Raman scattering from ($x^2-y^2$)to $xz$ / $yz$ $d$-orbitals of Fe.Comment: 19 pages, 4 figures, 1 tabl

Evolutionary Insights into the Enzymes involved in the Biosynthesis of the Volatile Organic Compounds Isoprene and Pinene in Plants

Volatile organic compounds (often abbreviated as VOCs) are emitted as secondary metabolites by plants, and contribute to a wide range of ecological processes, owing to their pivotal role in plant interactions with biotic and abiotic variables. As a result, they differ greatly between species and explain disparities in ecological strategy. In an effort to comprehend their genesis and assess potential evolutionary trends, this work probes into the enzymatic pathways that lead to their synthesis. Correspondingly, we adopt and propose an in-silico approach to analyze connections between the species evolution and the gene evolution of two major plant volatile organic compounds. We lay focus on isoprene and pinene, volatile organic compounds synthesized by two common yet compartmentally isolated pathways - the methylerythritol phosphate (MEP) pathway and the mevalonic acid (MVA) pathway, respectively. Analyses of gene-specific and protein-specific phylogenetic trees of the enzymes involved in these pathways thereby indicate a mixed trend in the evolution as per the APG IV (Angiosperm Phylogeny Group IV) system. These results and the in-silico pipeline thus provide us with future opportunities to explore different networks of plant communication for a holistic understanding of intraspecific and interspecific interactions in different natural ecosystems