Indian Journal of Physics最新文献

{"title":"Circularly symmetric Hermite-Gaussian correlated Schell-model beam","authors":"Mengyuan Guo,&nbsp;Kaixin Wu,&nbsp;Wenhui Yang,&nbsp;Yan Yang,&nbsp;Huilong Liu","doi":"10.1007/s12648-024-03402-1","DOIUrl":"10.1007/s12648-024-03402-1","url":null,"abstract":"<div><p>We introduce a novel class of random stationary, scalar source for producing far field with ring-shaped intensity profile, named as circularly symmetric Hermite-Gaussian correlated Schell-model (CSHGCSM) source. The analytical expressions for the cross-spectral density (CSD) function of a CSHGCSM beam propagating in free space and in linear isotropic random media are derived, respectively. It is shown that the CSHGCSM beam exhibits a robust ring-shaped profile in far field, and three-dimensionally (3D) optical cage could be obtained when the CSHGCSM beam focused by a thin lens. The optical cage length is dependent on parameters of mode order <i>n</i>, transverse coherence width <i>δ</i>, focal length <i>f</i>, and beam wavelength <i>λ</i>. Furthermore, it is demonstrated that the CSHGCSM beam propagating in linear random media at small distance from the source exhibits annular profile, then converts into Gaussian beam as the propagation distance increases. There is a phenomenon of regenerative oscillation for the spectral degree of coherence (SDOC) of the CSHGCSM beam in the presence of random media.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 5","pages":"1881 - 1890"},"PeriodicalIF":1.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and performance evaluation of 2D nickel oxide nanosheet thin film electrodes in energy storage devices","authors":"Peeyush Phogat,&nbsp; Shreya,&nbsp;Ranjana Jha,&nbsp;Sukhvir Singh","doi":"10.1007/s12648-024-03415-w","DOIUrl":"10.1007/s12648-024-03415-w","url":null,"abstract":"<div><p>This research comprehensively investigates the structural, optical, and electrochemical properties of nickel oxide (NiO) nanoparticles, focusing on its potential applications in energy storage systems, particularly electrochemical double-layer capacitors (EDLCs). In a single-step hydrothermal process, two-dimensional (2D) NiO nanoparticles was synthesized using carbon templates. X-ray diffraction analysis confirmed NiO nanoparticle’s crystalline nature, revealing a crystallite size of approximately 35 nm. Optical characterization unveiled NiO nanoparticle’s distinctive absorption pattern in the UV region, with additional absorbance observed in the visible region, and a calculated band gap of 2.6 eV. Morphological studies depicted a unique 2D nanosheets structure for NiO nanoparticles, with microstructural images showing fringe patterns and selected area electron diffraction patterns indicating its polycrystalline nature. NiO nanoparticles exhibit excellent electrochemical performance, including high specific capacitance, which is crucial for efficient energy storage. Their unique 2D nanosheet structure enhances surface area and facilitates better charge transport, making them ideal for EDLCs. Additionally, the reduced band gap of NiO nanoparticles, as determined in this study, improves their conductivity and overall electrochemical behavior. These novel attributes position NiO nanoparticles as superior materials for advancing the performance and efficiency of energy storage devices. Crucially, NiO nanoparticles exhibited a high specific capacitance of 13 F/g, highlighting its suitability for EDLCs. This finding positions NiO nanoparticles as a promising candidate for energy storage applications, advancing the field of supercapacitors. Electrochemical analysis through cyclic voltammetry and Nyquist plots further elucidated the material's potential in energy storage applications. This interdisciplinary exploration enriches our understanding of NiO nanoparticles and underscores its utility in emerging energy storage technologies, guiding further advancements in supercapacitor systems for sustainable energy solutions.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 5","pages":"1679 - 1690"},"PeriodicalIF":1.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Eu-doping on transport properties of synthesized zintl phase compounds EuxYb1−xZn2Sb2 under microwave-assisted solid-state","authors":"Ibrahim Majeed Jasim,&nbsp;A. Hmood","doi":"10.1007/s12648-024-03404-z","DOIUrl":"10.1007/s12648-024-03404-z","url":null,"abstract":"<div><p>In this work, synthesis and characterization of Eu_xYb_1−xZn₂Sb₂ (0 ≤  ×  ≤ 1.0) systems under microwave irradiation method. Herein, microwave technique offers ecological merit in the synthesis of thermoelectric materials such as short duration (25 min). The synthesized samples were analyzed by their XRD, SEM, EDX, Seebeck coefficient, electrical conductivity, and Hall voltage measurements. The microwave synthesis of compounds by doping Eu into YbZn₂Sb₂ and their properties are extensively discussed. It was found that the microwave irradiation acts to accelerate the reactions induced by fast heat surrounding susceptor of primary components and give large quaternary ingots. The XRD data revealed that the synthesized compounds crystallized in a hexagonal structure where ZnSb precipitated as a secondary phase in almost all the synthesized adopted compounds. Furthermore, a maximum PF of 26.27 μW/cmK² at 518 K was acquired for Eu_0.6Yb_0.4Zn₂Sb₂ sample with carrier concentration of 5.11 <span>(times )</span> 10²¹ cm⁻³ at 300 K.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 5","pages":"1651 - 1658"},"PeriodicalIF":1.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved thermal conductivity and its application","authors":"Priyanka Sahare,&nbsp;Bijay Kumar Sahoo","doi":"10.1007/s12648-024-03393-z","DOIUrl":"10.1007/s12648-024-03393-z","url":null,"abstract":"<div><p>The quantum efficiency of GaN/ Al_xGa_1−xN/GaN superlattice (SL) UV-LED is reduced as a result of temperature rise in the active region of the LED. Self-heating of the device due to the temperature rise strengthens non-radiative processes, low internal efficiency, and a small lifetime of the LED. In this work, it is found that poor heat dissipation from the device due to low thermal conductivity (<i>k</i>) of the SL is one reason for temperature rise. In this investigation, we found that a 15% enhancement in <i>k</i> reduces a 7% temperature rise. A strategy of structural optimization has been carried out to demonstrate the improvement in <i>k.</i> It can be improved by managing the well barrier thickness ratio (<i>r</i>) in the SL. In this study, we found that for <i>r</i> &lt; 1, <i>k</i> shows considerable enhancement. This well barrier thickness tailoring technique has two significant consequences: 1. improvement in <i>k;</i> 2. suppression of the detrimental effect of polarization on <i>k</i>. This work suggests that composition <i>x</i>, and structural optimization (well barrier thickness engineering), have a vital role in thermal conductivity management in SL, which can reduce the rise in temperature resulting in the high quantum efficiency of the UV-LED.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 4","pages":"1393 - 1400"},"PeriodicalIF":1.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Realistic fermion mass and mixing in (mathbf {U(1)_L}) model with (mathbf {A_4}) flavor symmetry for majorana neutrino","authors":"V. V. Vien","doi":"10.1007/s12648-024-03375-1","DOIUrl":"10.1007/s12648-024-03375-1","url":null,"abstract":"<div><p>We propose a <span>(U(1)_L)</span> model based on <span>(A_4)</span> symmetry aiming to explain the smallness of neutrino masses as well as the quark and lepton mixing patterns. The smallness of Majorana neutrino mass is reproduced through the combination of type-I and -II seesaw mechanisms. The model can accommodate the current observed patterns of lepton and quark mixing in which the solar neutrino mixing angle and the Dirac CP violating phase are in <span>(3sigma )</span> range for both normal hierarchy and inverted hierarchy, the Majorana violating phases are predicted to be <span>(eta _{1} in (0.00, 9.76)^circ )</span> and <span>(eta _{2} in (68.70, 270.00)^circ )</span> for normal hierarchy while <span>(eta _1in (0.00, 10.83)^circ )</span> and <span>(eta _{2} in (78.60, 90.00)^circ )</span> for inverted hierarchy. The obtained sum of neutrino mass and the effective Majorana neutrino mass are in good consistent with the recent limits. For quark sector, all the quark masses can get the best-fit values and all the elements of the quark mixing matrix are in agreement with the experimental constraints except the element <span>( (V_{{{text{CKM}}}} )_{{21}} )</span> with a deviation about <span>(0.25,%)</span>.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"1165 - 1183"},"PeriodicalIF":1.6,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sharma-mittal HDE model in anisotropic universe","authors":"T. Vinutha,&nbsp;K. Niharika,&nbsp;K. Venkata Vasavi","doi":"10.1007/s12648-024-03374-2","DOIUrl":"10.1007/s12648-024-03374-2","url":null,"abstract":"<div><p>The current study explores the Sharma-Mittal holographic dark energy (SMHDE) by considering Bianchi-<span>(VI_0)</span> space-time in Saez-Ballester’s theory. The model’s exact solutions are procured by assuming the relationship between metric potentials. The Hubble horizon is regarded as the Infrared cutoff to examine our model’s cosmic effects. The physical behavior of the model is investigated by considering two fluids- SMHDE and pressureless matter. The behavior of the cosmological parameters, such as the deceleration parameter, EoS parameter, <span>(rho _{de})</span>, <span>(rho _m)</span>, statefinder, and <span>(v_s^2)</span>, was evaluated with the help of their plots with respect to redshift(<i>z</i>) to study the nature of the universe. The figure of the deceleration parameter predicts that the present model transits from the deceleration to the acceleration period of the universe. The EoS parameter for this model agrees with the recent astrophysical observations, which lie within the range of quintessence region. In the case of statefinder and <span>(v_s^2)</span>, the model shows Chaplygin gas and stability throughout the region. The perturbation technique is used to evaluate the stability of the resulting model. Finally, the results of the current model support the existence of an accelerating universe with the present observational data.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 5","pages":"1939 - 1951"},"PeriodicalIF":1.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of magnetic field on the Rashba spin–orbit interaction in an asymmetry quantum well","authors":"Shan Shuang, Lan Hong, Jun Ge, Da.-Quan Liu","doi":"10.1007/s12648-024-03376-0","DOIUrl":"https://doi.org/10.1007/s12648-024-03376-0","url":null,"abstract":"<p>The effects of a magnetic field on the Rashba spin–orbit interaction in an asymmetry quantum well is theoretically studied, and the expression of the ground state energy of the magnetopolaron is obtained within Pekar variational method. The ground state energy of the magnetopolaron splits into two branches due to the Rashba effect, and the energy splitting appears saturated state with the increase of the well width. Because the contribution of the magnetic field cyclotron resonance frequency to the Rashba spin–orbit splitting is a positive value, the energy splitting distance becomes larger as the magnetic field cyclotron resonance frequency increases. Due to the spin–orbit interaction, the energy splits at zero magnetic field. The total energy is reduced due to the existence of phonons. Therefore, the polaron state is more stable than the bare electron state, and the polaron energy splitting is more stable.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"6 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First principles insight into magneto-electronic and optical properties of half-metallic-ferromagnetism binary GaN compound for spintronic applications","authors":"Nazia Iram,&nbsp;Aparna Dixit,&nbsp;Bandar Ali Al-Asbahi,&nbsp;Ramesh Sharma,&nbsp;Javed Ahmad,&nbsp;Zubair Ahmad,&nbsp;Imad Barsoum","doi":"10.1007/s12648-024-03240-1","DOIUrl":"10.1007/s12648-024-03240-1","url":null,"abstract":"<div><p>In this paper, we compare pure and doped GaN under spin ferromagnetic and non-magnetic calculations using the Full Potential Linearized Augmented Plane-wave method and the state-of-the-art computational code WIEN2k. Structural and opto-electronic aspects of GaN have been studied by implications of corresponding potentials and exchange–correlation energy functional. Though, to yield bandgaps in good agreement with the experiment study, Tran–Blaha modified Becke–Johnson (mBJ) potential has been employed. In order to determine the band gap, reflectivity, refraction, refraction index, lattice constant, dielectric constant, and energy loss spectrum for GaN, these simulations were carried out. Good agreement with experimental measurements has been observed throughout this investigation. In addition, O-doped GaN exhibits prominent absorption peaks in the high energy region, indicating potential applications in UV optoelectronics and spintronics.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 1","pages":"33 - 41"},"PeriodicalIF":1.6,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Valley polarization of electrons in a graphene under modulations of the electrostatic potential barrier and the magnetic field","authors":"R. S. Luo,&nbsp;J. D. Lu,&nbsp;X. Y. Li,&nbsp;H. Wang","doi":"10.1007/s12648-024-03390-2","DOIUrl":"10.1007/s12648-024-03390-2","url":null,"abstract":"<div><p>The valley polarization is a fundamental concept in valleytronic applications. However, the combined effects of the electrostatic potential barrier and the magnetic field as well as strains on the valley polarization in a graphene have been rarely reported. Therefore, in this paper, we use the transfer-matrix method to illustrate effects of the height and width of the electrostatic barrier and the strength of the applied magnetic field on the valley polarization of electrons in a graphene, and we find that the valley polarization strongly depends on the strength and width of the electrostatic barrier. We also find that the 100% valley polarization can be achieved continuously and smoothly over a wide range of Fermi energy region by controlling the strength of the applied magnetic field. This point makes it easier to design novel valleytronic devices based on graphene with the presence of the magnetic field and the electrostatic potential barrier as well as strains.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 4","pages":"1379 - 1385"},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lie symmetry approach for shock wave propagation in a self-gravitating non-ideal gas under the influence of monochromatic radiation and magnetic field in rotating medium","authors":"G. Nath,&nbsp;P. Upadhyay","doi":"10.1007/s12648-024-03352-8","DOIUrl":"10.1007/s12648-024-03352-8","url":null,"abstract":"<div><p>The propagation of cylindrical shock wave influenced by monochromatic radiation and magnetic field in a self-gravitating non-ideal gas for a rotating medium has been investigated by using the Lie symmetry method. Ahead of the shock front, the ambient density of the medium is taken as constant, while the magnetic field, azimuthal and axial velocities vary over time. By using the Lie symmetry approach, the optimal system for the governing equations, the similarity variable and transformations are obtained. By the use of derived similarity transformations, the governing equations change into a system of ODEs (ordinary differential equations). The software package “Mathematica” has been utilized to solve the system of ODEs numerically and to generate the graphs for the flow variables distribution. In this article, the strength of the shock wave and variations in the flow variables of the flow field region behind the shock front, which are influenced by the strength of the ambient magnetic field, gravitational parameter, non-idealness parameter, adiabatic exponent, and rotational parameter, are examined in detail. It has been demonstrated that the magnetic field, non-idealness parameter, adiabatic exponent, and rotational parameter have decaying effect on the shock wave. In contrast, the gravitational parameter has reversed impact on the shock strength.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 4","pages":"1519 - 1540"},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}