SPIN

Spin caloritronic devices, multifunctional devices combining spintronics and caloritronic, are crucial for the sustainable development of humans. A novel spin caloritronic device is presented using anthraquinone-based molecular sandwiched among two semi-infinite zigzag graphene nanoribbons containing asymmetrical edge hydrogenation electrodes. We demonstrate that the temperature gradient between the right and the left electrodes can generate spin-up and spin-down currents flowing in opposite orientations. Besides, the mentioned currents possess approximately the same magnitudes, indicating a nearly nondissipative spin Seebeck effect. We also find that these currents are significantly dissimilar for the redox reactions and force at different temperature gradients, demonstrating that the developed system can provide acceptable switching action. The obtained results reflect that the redox reactions and force can control the spin Seebeck effect.

The magnetic properties and phase diagrams of a ferrimagnetic cylindrical Ising nanotube with spin-1/2 core and spin-3/2 shell are studied using mean-field approximation and Monte Carlo simulation. The effects of shell and core-shell interface exchange couplings and crystal field on the magnetic properties of the system are examined. For some physical parameters, the critical and compensation behaviors are highlighted and first-order phase transitions are observed in the ferrimagnetic ordered region at low temperatures. A comparison between the two methods was performed.

The statement that any phase transition is related to the appearance or disappearance of long-range spatial correlations and precludes a finite transition temperature in one-dimensional (1D) systems is rooted in condensed matter theory. In this paper, we demonstrate that the 1D Ising model with short-range exchange interactions exhibits a second-order phase transition at a finite temperature relying on the proper choice of the order parameter. We combined analytical calculations and high-precision entropic sampling simulations and chose a slightly different order parameter, namely, the modulus of the magnetization. Notably, we detected a phase transition with a corresponding critical temperature around 15 K, which is in excellent agreement with experimental results. Our study indicates that the incorrect choice of the order parameter may mask phase transitions in 1D systems.

In this paper, structural, elastic, electronic and magnetic properties of half-Heusler XSrC ($\mathrm{\text{X}}=\mathrm{\text{Li}}$ and Na) compounds have been investigated utilizing full potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT). For exchange-correlation potentials, the generalized gradient approximation (GGA) has been used. The calculated cohesive and formation energy values showed that these compounds can be experimentally synthesized. The elastic properties were analyzed in detail and reveal that LiSrC and NaSrC compounds are mechanically stable. The spin-polarized band structure and density of states illustrate that LisrC and NaSrC alloys have a half metallic character. The total magnetic moment is 1$\mu \mathrm{\text{B}}$ per formula unit that confirms the half metallic behavior and follows the Slater-Pauling rule $M_T=(8-Z_{\mathrm{\text{tot}}}){\mu }_B$. For half-Heusler XSrC ($\mathrm{\text{X}}=\mathrm{\text{Li}}$ and Na) compounds, there are no available experimental or theoretical studies, our calculations are considered as first predictions.

In this paper, the synthesis and characterization (structural, dielectric, electrical and optical) of a double perovskite, BaSrZrMnO₆ (BSZMO), by a conventional solid-state reaction route are reported. The sample has an orthorhombic crystal symmetry with an average crystallite size of 40.7nm and a micro-lattice strain of 0.226%. A microstructural and compositional analysis was presented by using a scanning electron microscope (SEM) and energy dispersive x-ray analysis (EDX), respectively. Grains are well-grown and distributed uniformly through well-defined grain boundaries on the sample surface to enhance physical properties. EDX analysis confirms the presence of all constituent elements and is well-supported by the Raman study. The analysis of the UV–Visible spectrum reveals an energy bandgap of 2.1eV, suitable for photovoltaic applications. The study of dielectric properties as a function of temperature and frequency reveals a Maxwell–Wagner type of dispersion and explores possible applications in energy storage devices. The discussion on the impedance spectroscopy supports the negative temperature coefficient of resistance (NTCR) character whereas the modulus study suggests a non-Debye type of relaxation in the sample. The study of AC conductivity confirms a thermally activated relaxation process. Both Nyquist and Cole–Cole plots support the semiconducting nature of the sample. The study of resistance versus temperature ($R\sim T$) supports NTC thermistor character for temperature sensor applications. The analysis of the P-E loop reveals the possibility of the ferroelectrics’ character.

In this paper, we theoretically investigate how to control spin filtering via a $\delta$-doping for electrons in a magnetically and electrically modulated semiconductor nanostructure (MEMSN), which can be realized by patterning a ferromagnetic (FM) stripe and a Schottky-metal (SM) stripe on top and bottom of GaAs/Al_xGa${}_{1-x}$As heterostructure in experiments, respectively. A considerable spin filtering effect still exists because of spin–orbit coupling (SOC), even if a $\delta$-doping is included. Moreover, spin polarization ratio can be manipulated by $\delta$-doping, which may lead to a structurally-controllable electron-spin filter for semiconductor spintronics.

Rendering is a computer graphics process that generates images from a three-dimensional scene including models, lights and cameras. Ray tracing is a category of rendering algorithms that calculates pixel colors by simulating the physical movements of light rays such as reflections, refractions and scatterings. The core problem of ray tracing is a high-dimensional numerical integration, and the classical Monte Carlo ray tracing requires a big number of rays to reduce error. By leveraging the inherent parallelism of quantum computing, we propose a framework of quantum ray tracing algorithm, and do simulation experiments to prove that it has a quadratically faster error convergence than classical Monte Carlo ray tracing.

In this study, we investigated the dielectric properties of ovalene-like nanostructure with RKKY (Ruderman–Kittel–Kasuya–Yoshida) interactions, using Monte Carlo simulations. Nanosystem consists of an ovalene-like nanostructure with mixed spins $\sigma$-7/2 and S-1, separated by non-electric layers (NEL). We investigated the effect of the non-electric layers, external longitudinal electric field and ferrielectric exchange coupling on polarization and dielectric susceptibility of the nanostructure. We find that the transition temperature is affected by an increase in the number of non-electrical layers. These results can enrich the dielectric properties of ovalene-like nanostructure for future nanotechnology applications.