The polycrystalline compound Ho2CoMnO6 was synthesized by the conventional solid-state process. Its structure has been solved by X-ray powder diffraction (XRD) indicating that this double perovskite adopts a monoclinic structure with the space group P21/n. The fundamental optical properties were extracted using UV–visible measurements. The optical absorption is obtained around 590 nm and a direct optical

Electronic and magnetic properties of a system of two charged vacancies in hexagonal shaped graphene quantum dots are investigated using a mean-field Hubbard model as a function of the Coulomb potential strength β of the charge impurities and the distance R between them. For β=0, the magnetic properties of the vacancies are dictated by Lieb’s rules where the opposite (same) sublattice vacancies are

Four tetragonal anisotropic superhard carbon phases, T-C8, T-C12, T-C20 and T-C28 were generated by RG2 program, T-C8 has been reported and named bct-Carbon. The calculated relative enthalpy, elastic constants and phonon dispersion spectra show that these structures are stable. Their lattice failure modes are mainly tensile. Thermodynamic stability, thermal performance and hardness are all in the order

First-principle calculations have been performed to investigate electronic structures and magnetic properties of Fe doped and (Fe, Ni) codoped InN within the generalized gradient approximation + U and plane-wave ultra-pseudopotential schemes. The results demonstrate that the formation energy of Fe doped and (Fe, Ni) codoped InN is negative and the doped systems have better stability. It is found that

Metal single-electron transistor (SET) and semiconductor quantum dot (QD) are Coulomb blockade (CB) devices having applications in quantum and classical technologies. The quantized confined energy of the confining system increases when the size of this system decreases. This behavior affect transport of charge carrier through SET significantly. This paper presents the results of investigation on the

In this paper, the influence of impurity parameters on the energy-dispersion spectrum of electrons and holes in a doped quantum wire with Gaussian impurity is studied. The numerical calculations have shown that the energy eigenvalues enhance, if the confinement of carriers increases. Then, the energy eigenvalues rise when the magnetic field, decay length and strength of impurity increase. Also, the

In this paper, we study the influence of periodically driven circularly polarized light on the band structure and transport properties of borophene at high frequency limit. We predict the topological phase transition of borophene from Dirac semimetal to Floquet topological insulator under circularly polarized light by analyzing the anomalous Hall conductance and Chern number. Moreover, due to the inversion

The XXZ Heisenberg model is used to study the dispersion relation of spin waves propagating in decorated planar square and triangular lattices. A superposition of interpenetrating lattices will be used to generate the composed systems. The decorations are introduced in order to generate systems with more than one atom per unit cell. The formalism applied here allows us to study different types of decorated

We report the structural, magnetic, magnetocaloric properties, and the critical behavior of the NiCeFeO4 spinel ferrite synthesized via the sol–gel method. The XRD analysis has revealed that NiCeFeO4 belongs to the Fd-3m space group of the cubic spinel structure. Furthermore, magnetic properties demonstrate that the prepared sample undergoes a second-order ferromagnetic-paramagnetic (FM-PM) phase transitions

We have investigated the structural, mechanical, electronic, thermodynamics, and superconducting properties of new ternary equiatomic pnictides LaIrP and LaIrAs superconductors using first-principles density functional theory (DFT) calculations for the first time. Theoretical Vicker's hardness and chemical bonding have also been estimated for these compounds. All the investigated results are compared

We investigate whether the thin-film carbon Raman spectral form is determined by the location of the corresponding sample within the framework of a ternary phase characterization of thin-film carbon. We do this through a critical examination of a collection of experimentally acquired Raman spectra corresponding to an ensemble of thin-film carbon samples, whose sp2 and sp3 bonding contents and hydrogen

We present the phonon-limited electron mobility in planar T graphene and find that the mobility ∝T−5.53 at low temperature T. With the increase of temperature, the power exponent 5.53 decreases towards 1. Excitingly, the room-temperature mobility of planar T graphene is 2.78×106 cm2/Vs which is about 20.59 times as large as that of n-type graphene at the same carrier density. Different from graphene

LiZnPS4 is thought to be a promising mid-infrared optical crystal and lithium battery material, but its fundamental properties are still not well investigated. In this work, we performed a systematic study on its electronic, elastic, infrared and electrical properties. The results indicate that LiZnPS4 is an indirect band gap crystal. Calculated partial density of states reveals that the top of its

A method is proposed for calculating the lattice parameter (l) for the solid solution (i.e. disordered binary substitutional alloy), which takes into account the pressure (P) in the alloy. An analytical expression is obtained for calculating the dependence of the function l on the alloy concentration at different values of P. It is shown that for P = 0 the deviation from the Vegard's law (Δl) is due

In this research, the hydrostatic pressure effects on the transmission spectra of a one-dimensional (1D) defective phononic crystal (PnC) are calculated and studied. The transmission spectra of the defective PnC are calculated based on the transfer matrix method (TMM). To measure the hydrostatic pressure efficiently, a pressure-sensitive material such as Poly (methyl methacrylate) (PMMA) is proposed

The crystal, electronic, magnetic and optical properties of the Sr2CaOsO6 double perovskite compounds have been investigated in this work, using density functional theory as implemented in the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method, employing the Generalized Gradient Approximation (GGA-PBE), GGA + U (Hubbard Coulomb correction) and GGA plus Trans-Blaha-modified Becke–Johnson

Elastic properties of zinc blende CdxZn1-xSySe1-y quaternary alloys have been calculated with density functional theory oriented FP-LAPW scheme. Elastic stiffness constants and hardness of specimens have been increased almost linearly with increasing sulphur composition at each fixed cadmium composition, while their decrease have been observed with increasing cadmium composition at each fixed sulphur

The quasiparticle band structures of monolayer α-ZrNX (X = Cl, Br, I) and β-ZrNX (X = Cl, Br, I) are researched by using an exact quasiparticle approximation GW theory. Our results show that both monolayer α-ZrNX (X = Cl, Br, I) and β-ZrNX (X = Cl, Br, I) are two-dimensional semiconductors with wide band gaps (larger than 3.5 eV). We have considered the effect of exciton, calculated their optical properties

Monolayer transition-metal dichalcogenides (TMDCs) with intrinsically broken crystal inversion symmetry have shown large second-order nonlinear responses, providing a new platform for nonlinear light-matter interaction engineering. Integrating two dimensional monolayers with nanoresonators has been demonstrated to enhance the second harmonic generation. Previous designs suffer from the drawbacks of

In this work, we study the magnetic properties of a nanotube core-shell like-structure using Monte Carlo simulations. The system consists of an anti-ferrimagnetic hexagonal core-shell nanotube like-structure with mixed spins σ = 1 in the core and S = 3/2 in the shell. We start by discussing the ground state phase diagrams corresponding to several physical parameters. Then the magnetizations and the

NbBiCh3 (Ch = S, Se) misfit-layered superconducting single crystals were successfully grown using a CsCl/KCl flux for the first time. The obtained crystals had a well-developed habit parallel to the c-plane with a typical width of 1–2 mm and thickness of 10–40 μm. The superconducting transition temperatures with zero resistivity of NbBiS3 single crystals obtained from the nominal composition of Nb0

Two-dimensional (2D) CrCl3 has attracted much attention as it is reported to be a ferromagnetic semiconductor. By performing first-principles calculations, we investigate the effects of Li and F adsorption on the saturation magnetization and magnetic anisotropy energy (MAE) of CrCl3. It is observed that Li adsorption can dramatically enhance its saturation magnetization, and tune its easy magnetization

The electronic structure and magnetic nature of Mn substitutional impurities (MnSi) in cubic silicon carbide (3C-SiC) are investigated based on first-principles calculations. Our studies revealed that MnSi impurity introduces a magnetic moment of 3.0 μB due to the unpaired d electrons of Mn atoms, and the surrounding C atoms play an important role for mediating the ferromagnetic (FM) coupling between

Investigations of equation of state (EOS) of LiNi0·5Mn1·5O4 under high pressure have been performed using synchrotron radiation X-ray diffraction (XRD) in a diamond anvil cell (DAC) at ambient temperature, density functional theory (DFT) calculations and Raman spectroscopy. It is found that the cubic structure maintains to the maximum pressure of 27.3 GPa by XRD and 21.0 GPa by Raman scattering. The

Theoretical study of the adsorption and dissociation of water on halogen pre-adsorbed Ni(111) and Ni–Cr(111) surfaces has been investigated systematically. The stable co-adsorption configurations and corresponding adsorption energies for H2O molecule and halogen atom were obtained. It was found that the halogen atom strengthens the interaction of H2O with Ni surfaces. The corresponding activation barriers

In this article, we study non-trivial topological phase and electron-hole compensation in extremely large magnetoresistance (XMR) material YSb under hydrostatic pressure using first-principles calculations. YSb is topologically trivial at ambient pressure, but undergoes a reentrant topological phase transition under hydrostatic pressure. The reentrant behavior of topological quantum phase is then studied

From the temperature dependent Raman spectroscopy study (80 K–300 K) on epitaxial thin film of lanthanum nickelate (LNO), we find that the characteristics Raman active phonon modes (A1g and Eg) of LNO soften with an increase in the temperature. The extent of softening is greater for the A1g mode owing to substrate induced strain. In addition, temperature dependent Raman shifts presented with some non-linearities

Polycrystalline NdAlGe intermetallic compound has been investigated with structural characterizations and magnetic measurements. NdAlGe consists of alternating stack of Ge3, Al3, and Nd3 isosceles triangles Δ in A layer and Nd3, Ge3, and Al3 reversal isosceles triangles ∇ in B layer along a axis. The non-centersymmetrically structure is built by connecting the rare earth Nd atoms in Nd3 Δ and Nd3 ∇

An analytical model to describe the interaction of excitons and charge transfer states with deep traps is formulated for the case of molecular materials. Here, we have considered the influence of a trap-assisted recombination on this phenomenon. The final expression for the effective recombination rate has been derived from the Shockley–Read–Hall theory and kinetic equations which characterize different

The 1.54 μm emission of Er3+ ions embedded in a dichroic Cu nanocomposite glass is shown to be either quenched or enhanced depending on the excitation wavelength. The synthesized material consisted of an aluminphosphate matrix co-doped with Cu and Er as prepared by thermal processing, and characterized by optical absorption and photoluminescence (PL) spectroscopy including an assessment of decay dynamics

This paper addresses the phenomenon of mode-mixing in the acoustic and optical branches of the vibrational modes of III-V compounds, and its effect on the electron-phonon interaction. A description is given based on the analytic lattice-dynamics model of long wavelengths in the diamond lattice based on valency force fields (VFF). This model is known to give good results for the acoustic elastic constants

Specific properties of quasicrystals (QCs) with regards to their structures are discussed with emphasis on diffusion process. To fulfil this, regular mechanisms in the solids are introduced. The experimental results show that the predominant mechanism in quasicrystals is phason which is caused by the absence of proper matching in their structure and the vacancies in the lattice. Monolayers of Al were

Chromium triiodide (CrI3) monolayer, as a two-dimensional (2D) intrinsic ferromagnetic (FM) semiconductor, creates a large number of opportunities for the spintronic application of atomically thin magnets. Using density functional theory, we studied the electronic structures and carrier doping of CrI3 monolayer with vacancy defects. The energy band structures show that the flat-bands near the Fermi

We investigated the crystal structure, electronic structure, elastic stiffness constants, responses to tensile and shear deformations, lattice vibrational modes as well as vibration heat capacity and vibration entropy of the orthorhombic YSi compound using ab initio approach. The relaxed ground-state lattice constants a, b and c of YSi exhibit fair agreement with the available experimental and theoretical

Hydrogen-rich materials have always attracted the interest for the crystal structures and electronic properties under high pressures. The crystal structures of alkaline earth compounds Mg(CH3)2 and Ca(CH3)2 have been predicted by employing a particle swarm optimization algorithm at high pressures. The P-3c1 phases of the both compounds were synthesized at about 17.5 GPa and 3 GPa, respectively. The

Silicon dioxide or quartz is one of the most important natural resources, and silicates are the prominent content of more than 90% of the earth's minerals. This research investigates the mechanical properties and thermal conductivity of α-quartz by using non-equilibrium molecular dynamics (NEMD) simulation method. The Beest, Kramer, and van Santen (BKS) pairwise interatomic potential suitable for quartz

We present a first-principles and experimental study of the structural, ferroelectric, and magnetic properties of the potentially multiferroic three-layer Aurivillius compound Bi4TiFeNbO12. This system can be realized by inserting a BiFeO3 formula unit into the two-layer Aurivilius Bi3TiNbO9 matrix. The calculations are performed using the PBEsol exchange–correlation functional within the DFT+U framework

Terahertz (THz) metamaterial absorbers are promised as one of the appropriate candidates for the biosensing and imaging novel devices. In this work, a wideband THz absorber consists of two periodic arrays of graphene ribbons (PAGRs) and one graphene continuous sheet (GCS) in a form of Fabry-Perot resonator is presented. Analytical circuit model of PAGRs and GCS in addition to a developed transmission

Neutron diffraction is used to reveal the origin of the unusual thermal expansion properties of the itinerant-electron system Hf0.875Ta0.125Fe2. Hf0.875Ta0.125Fe2 shows temperature-induced magnetic transitions from ferromagnetic (FM) to antiferromagnetic (AFM) order and then to the paramagnetic (PM) state upon heating. The FM-AFM transition proceeds in a stepwise fashion, as a first-order phase transition

Lead-based perovskite materials are commercially restricted as ideal candidates for solar cell applications due to their toxic nature. Here, we have performed a first-principles investigation of structural, mechanical and optoelectronic properties of the orthorhombic perovskite structures of MAGe1-xSnxI3 (MA = CH3NH3) by using density functional theory (DFT). In this research work, mixed Ge/Sn in different

The electrically excited impurity emission from AlGaN/GaN high electron mobility transistor (HEMT) structures in external magnetic field varying from 1.2 T to 1.5 T was investigated in this work at temperature of 4.2 K. We have observed the sharp emission line at (263 ± 1) cm−1 with FWHM of (5.8 ± 0.8) cm−1, which we have attributed to radiative electronic transitions in residual oxygen impurity atoms

The use of 2D transition metal-dichalcogenide (TMDC) layers in solid state structures has received increasing attention in recent times. Molybdenum disulfide (MoS2) is one of the most technologically important graphene-like two-dimensional (2D) transition metal dichalcogenides (TMDCs). They have been extensively studied, in part, because they do not have the small bandgap limitations in graphene. As

Defects in wide-band-gap semiconductors provide a pathway for applications in quantum information and sensing in solid state materials. The silicon vacancy in silicon carbide has recently emerged as a new candidate for optically controlled spin qubits with significant material benefits over nitrogen vacancies in diamond. In this work, we present a study of the coherence of silicon vacancies generated

The magnetic properties and magnetocaloric effect (MCE) in GdVO4 single crystal have been investigated systematically. In addition to the previously reported spin-flop transition at 1 T along the c-axis, other spin-flop transitions also occur along the a and b axes at 1.7 T. Meanwhile, prominent magnetic anisotropy is observed below the paramagnetic temperature, which leads to evident distinction of

Graphene has obtained a great interest both in research and industries due to its potential and promising physical, electrical and mechanical properties. While it has been widely researched for advanced applications, its fundamental properties are still being explored and have to be well understood. The physical properties such as specific surface area (SSA), inter-sheet distance (d-spacing) and Raman

The optoelectronic properties of CdTe quantum dots can be controlled through changes in size, geometry or composition and, since their structural and electronic properties are sensitive to modifications of atomic configuration, impurities, and dopants, it is necessary to understand the underlying phenomena employing quantum mechanics principles. To this end, we discuss the optical absorption of CdTe

OFETs with discontinuous accumulative heterojunction have been fabricated with the pair of pentacene and F16CuPc. Four structures were designed to compare the channel doping and enhancing electrode injection effects both caused by carrier accumulation at different positions in OFETs. The tunneling mechanism of enhancing electrode injection efficiency is further investigated. Moreover, the ELUMO of

The flexible nanocomposites of bismuth ferrite and polyvinylidene fluoride were prepared by the solution casting method. The X-ray diffraction technique confirms the presence of both the inorganic filler (bismuth ferrite) and polymer phases. Atomic force microscopy study shows the increasing values of root mean square (RMS) roughness in the nanocomposites. The modulus and impedance spectroscopy were

Single-phase polycrystalline Li2PdO3 has been synthesized at 640 ̊C in oxygen for the first time under ambient pressure. X-ray and neutron diffraction analyses show that the sample possesses a monoclinic layered structure belonging to the C2/m space group. Rietveld refinements of neutron powder diffraction data indicate ~10% Li–Pd site exchange and DIFFaX modelling manifest ~2% stacking faults present

We investigate the structural, electronic and optical properties of lead-free halide Cs2TiI6 halide perovskites using ab-initio calculations. It is shown that the Ti-based halide perovskites possess several interesting properties, including high stability, suitable bandgap, and excellent optical absorption. It is demonstrated that the Cs2TiI6 compound presents a bandgap energy value of 0.998 eV. The

In the modern era materials with high NLO efficiency, better mechanical and thermal properties are on leading edge and highly demanded for their efficient use in optical communication and fibers optics. In the present course of work, authors have grown successfully single crystals of l-alanine strontium chloride trihydrate(LASRT) by slow evaporation solution and slow cooling techniques so as to meet

The unique surface edge states make topological insulators a primary focus among different applications. In this article, we synthesized a large single crystal of Niobium (Nb)-doped Bi2Se3 topological insulator (TI) with a formula Nb0·25Bi2Se3. The single crystal has characterized by using various techniques such as Powder X-ray Diffractometer (PXRD), DC magnetization measurements, Raman, and Ultrafast

The band structure, density of states (DOS), and electrical conductivity (EC) of different configurations of a double-strand poly-GC-poly-AT DNA-like nanowire are investigated within the tight-binding Hamiltonian model and the Green's function formalism. Three different configurations of the double-strand DNA-like nanowire were considered: infinite, finite, and cyclic. The change of behavior in the

The aim of this study is to calculate the structural, electronic and optical properties of M1-xPrxF2+x (M = Ba, Ca, x = 0.25). The calculations are performed by the spin-polarized density functional theory (DFT) combined with Hubbard U correction method. The band gaps of Ba0.75Pr0.25F2.25 and Ca0.75Pr0.25F2.25are calculated and compared to the binary fluorides BaF2 and CaF2. It is found that the band

Hexagonal Fe2P is an iron binary known to present a particularly large magnetocrystalline anisotropy potentially interesting for permanent magnets. However, its Curie temperature is far too low for applications. Here, we investigate the structural and magnetic phase diagrams of Fe1.95-xNixP1-ySiy quaternary alloys, looking for a possibility to combine high Curie temperature and uniaxial magnetic anisotropy

A new superhard carbon allotrope oC48 is uncovered. The mechanical and electronic properties of oC48 were studied by using first principles calculations. The calculated results of elastic constants and phonon dispersion show that oC48 is mechanically and dynamically stable. The hardness of oC48 is predicted to be 73.3 GPa, which indicates the superhardness of oC48. The elastic anisotropy of oC48 were

The elastic properties of Cu − Al − Mn alloys with compositions along the Cu3Al → Cu2AlMn line and bcc-based structures, are studied by means of first-principles calculations. From the calculated elastic constants, the Zener's anisotropy, sound velocities and Debye temperature are determined. The theoretical results compare well with the available experimental data. The influence of vibrations is introduced

Here, we synthesized monolayer MoS2 under atmospheric pressure by chemical vapor deposition (CVD) using a quartz tube with a large-diameter up to 100 mm. The morphology of MoS2 thin films along the airflow direction was initially observed by the optical microscope. Raman spectra and atomic force microscopy (AFM) were utilized to characterize the thickness of samples. Moreover, the optical properties