Indian Journal of Physics最新文献

To create granular materials with exceptional magnetoresistance properties, immiscible alloys were ball-milled in RSP (rapid solidification processing) ribbon. A system based on copper (Cu–Co) has been investigated. For Cu–Co–Ti, a single supersaturated solid solution has been found. The addition of Ti to Cu–Co substantially increases its solid solubility. The evolution of phase (s) during rapid solidification, and mechanical alloying followed by isothermal annealing were characterized using various techniques including differential thermal analyzers, High-resolution transmission electron microscopy, and X-ray diffraction. This study extensively used the superconducting quantum interference device magnetometer to observe magnetic behavior. The Cu–Co–Ti alloy from the ball milling RSP ribbon process was annealed at 550 °C for 1 h to get the favorable combination of magnetic characteristics. An in-depth theoretical analysis of the magnetic properties was conducted through the application of the 'VAMPIRE' software package, employing Monte Carlo Simulation as the underlying methodology.

In this paper, we study the saturation effect in the energy or mass spectra of three quantum models with energy-dependent potentials: the harmonic oscillator, the hydrogen atom, and the heavy quarkonia. We used the method proposed in [García-Martínez (Phys Lett 373:3619, 2009)], which is based on studying various canonical point and gauge transformations applied to a function, g(x), multiplied by a given differential equation of known solutions as special orthogonal functions, that convert it into a Schrödinger-like equation. The first two models stem from implementing the method on the confluent hypergeometric differential of the well-known solutions ( _1 F_1), while the third model (heavy quarkonia) stems possibly from the hypergeometric differential of the well-known solutions ( _2 F_1). In particular, the heavy quarkonia mass spectra for both (cbar{c}) and (bbar{b}) are produced at different values of the saturation parameter (lambda ) and compared with the available experimental data. It is found that these systems may exhibit saturation effect when the energy-dependent effect is included.

Vanadium pentoxide (V₂O₅) thin films were deposited onto glass and p-type silicon substrates via spray pyrolysis by using a perfume atomizer. The surface morphology of thin film was analyzed by atomic force microscopy. Structural and optical characteristics of the deposited thin films were assessed through X-ray diffraction and UV–Vis spectroscopy, respectively. The V₂O₅ thin films were determined to be polycrystalline in nature, exhibiting a band gap of 2.20 eV. The semiconductor properties of V₂O₅ thin films deposited on glass substrates were investigated through electrical measurements conducted by using a two-probe system across a range of temperatures. Key electrical parameters such as sheet resistance, conductivity, and activation energy were deduced from these measurements. Furthermore, the electrical characteristics of the Ag/V₂O₅/p-Si heterojunctions were scrutinized via current–voltage (I–V) and capacitance–voltage (C–V) analyses, which exhibited pronounced rectifying behavior in the Ag/V₂O₅/p-Si device structure.

There is a high demand for nuclear data in multidisciplinary subject like nuclear astrophysics. The two areas of nuclear physics which are most clearly related to one another are stellar evolution and nucleosynthesis. The necessity for nuclear data for astrophysical applications puts experimental methods as well as reliability and predicative ability of current nuclear models to the test. Despite recent, considerable advances, there are still significant issues and mysteries. Only a few characteristics of nuclear astrophysics are covered in the current work which include (^{52})Fe(n,(gamma ))(^{53})Fe, (^{53})Fe(n,(gamma ))(^{54})Fe, (^{54})Fe(n,(gamma ))(^{55})Fe, (^{55})Fe(n,(gamma ))(^{56})Fe, (^{56})Fe(n,(gamma ))(^{57})Fe, (^{57})Fe(n,(gamma ))(^{58})Fe and (^{58})Fe(n,(gamma ))(^{59})Fe reactions which are important in stellar nucleosynthesis. The reaction rates are calculated using nuclear statistical model. These rates are subsequently fitted to polynomials of temperature T(_9) in order to facilitate calculations for stellar nucleosynthesis.

This study investigates the characteristics of the vertical component of the ionospheric F2 layer plasma drift over the mid-latitude station of Nicosia, Cyprus ((hbox {35}^{circ }hbox {N}), (hbox {33}^{circ }hbox {E}), at magnetic dip angle, (hbox {I}=hbox {51.7}^{circ })), during pre- and post-sunset hours using digisonde data from November 2013 to October 2014. The observations demonstrate significant seasonal dependence in the vertical plasma drift during post-sunset hours. Vertical velocity shows a regular upward enhancement and notable oscillations during the evening in all seasons, with time variation dependent on the seasonal variability of sunset. The upward enhancement during sunset is typically attributed to chemical loss. However, the present study shows that the critical plasma frequency does not decrease significantly during sunset. Therefore, the observed velocity enhancement may not be solely attributed to recombination effects after sunset. It might be influenced by wind-driven electric fields. Wavelet analysis reveals wave activity around sunset, suggesting that the oscillations may be excited by the Solar Terminator.

Transfer-matrix method (TMM) in optics serves as a robust mathematical formalism for determining the transmittance of electromagnetic waves through a slab, thin film, or multi-layered structure. A plane electromagnetic (PEM) wave impinges at an angle to the normal of a slab or multi-layered structure and interacts with the material. A portion of this light passes through the first interface and then propagates in the material. Finally, it leaves the second interface of the material and carries information about the material. This formalism models the experimental transmittance spectra of (WO_3) thin film prepared by a thermal evaporation method. The spectral variations of the transmission coefficient and refractive index of (WO_3) are derived using the TMM approach, demonstrating concordance with the experimental data.

The goal of this work is to examine the effect of the gravity on a nonlocal fiber-reinforced half-space with reference temperature-dependent material properties. The three-phase lag model, the type III Green–Naghdi theory, and the Lord–Shulman theory all with memory-dependent derivatives are taken into consideration while analyzing the issue. To derive the precise formulations of physical fields, the harmonic wave analysis method is used. To quantify the impact of temperature-dependent on the characteristics of the medium and gravity, graphs are used. It is found that the physical quantities are affected by gravity, the nonlocal parameter, and reference temperature-dependent material properties. The method that was used in the present article is applicable to a wide range of problems in hydrodynamics and thermoelasticity.

The observation of coherent elastic neutrino nucleus scattering by the COHERENT collaboration alongside a positive hint from the DRESDEN−II experiment propelled the study of neutrino physics beyond the Standard Model. In the current work we have explored the light mediator models scenario, along with the neutrino non-standard interactions. Apart from a very good sensitivity to study these physics scenarios, reactor neutrinos provide the benefit of working in the fully coherent region due to their abundant low energy flux. The analyzed data set in the present work comprised of 124.2(70.3) kg day reactor ON(OFF) exposure collected at Kuo-Sheng neutrino laboratory with high purity n-type point Germanium detector. To assess the potential influence of the quenching factor on the limits obtained, we varied the parameter k in the Lindhard model within three scenarios: conservative (0.157), intermediate (0.200), and optimistic (0.260). These choices encompass a range of currently favored values. In the absence of any discernible excess at low energy in the measured spectrum for the considered physics scenarios, we have established competitive limits with the contemporary experiments specifically focused to search for coherent elastic neutrino nucleus scattering.

Recent research in environmentally friendly lead-free perovskite solar cells have made tremendous progress with their rapid improvements in performance and on the verge of commercialisation. In this research, a numerical simulation-based analysis of MASnI₃ with different transport layer materials are performed to enhance the efficacy. The finding shows, an optimized device architecture comprising of Cu₂O as a hole transport layer and TiO₂ as an electron transport layer achieves the highest power conversion efficiency of 27.21%, open-circuit voltage of 0.99 V, short circuit current density of 33.83 mA/cm², and fill factor of 81.12%, respectively. Moreover, the proposed model results have been compared with the recently published lead-free literature and found to have improvement in performance. Furthermore, the impact of several significant parameter on system performance is thoroughly analysed and optimised. This covers effect of temperature change, absorber thickness, total defect density, acceptor density of absorber along with others. Henceforth, the proposed research work will expand the possibilities of designing high-performance lead-free perovskite solar cells experimentally in future research.

This article considers the Cauchy reaction-diffusion equations and derives the numerical solutions using the fractional natural decomposition method (FNDM). The projected solution approach works without conversion or perturbation. The examples confirm the method’s accuracy and reliability, allowing for fractional order studies in real-world problems. Plots and tables validate the accuracy of the proposed scheme. This research reveals the influences of temporal history in the fractional Cauchy reaction-diffusion equations, which is the novelty of this work.