Indian Journal of Physics最新文献

{"title":"Q-switched and mode-locked pulsed laser with mechanically exfoliated V2ZnC MAX saturable absorber in erbium-doped all-fibre laser","authors":"Kawther M. Musthafa,&nbsp;Azura Hamzah,&nbsp;Ooi Wei Ling,&nbsp;Ahmad Haziq Aiman Rosol,&nbsp;Norliza Mohamed,&nbsp;Sulaiman Wadi Harun","doi":"10.1007/s12648-024-03313-1","DOIUrl":"10.1007/s12648-024-03313-1","url":null,"abstract":"<div><p>Researchers have proposed diverse techniques for fabricating saturable absorbers, including aqueous acid exfoliation, evanescent coupling, and electrochemical exfoliation, with fabrication complexity and limitations that reduce saturable absorber performance and application range. We describe mechanical exfoliation and transfer as an efficient and straightforward mechanism for a MAX phase nanomaterial, <i>V</i>_<i>2</i><i>ZnC</i>, expelled into a 48.926 µm thin saturable absorber film for passively Q-switched and mode-locked all-fibre lasers, exhibiting a modulation depth of 13.16%, non-saturable absorption to be 10.21%, and saturation intensity of 4.32 kW/cm² MAX-SA; all of which demonstrated its superiority with a self-starting laser. The output laser was stable with a pulse width of 7.160 µs and a repetition rate of up to 62.23 kHz at a threshold pump power of 59.53 mW in Q-switched conditions and 346.8 ns pulse width with 963.3 kHz repetition rate at a pump power of 80.41 mW in mode-locked conditions. It is a excellent saturable absorber for the use of pulse laser production in all-fibre laser cavities because of its simple manufacturing process and outstanding optical, physical, thermal, and mechanical qualities.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 2","pages":"705 - 714"},"PeriodicalIF":1.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141923270","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":"Anisotropic star with a linear equation of state (EOS)","authors":"Rinkal Patel,&nbsp;B. S. Ratanpal,&nbsp;Ranjan Sharma","doi":"10.1007/s12648-024-03297-y","DOIUrl":"10.1007/s12648-024-03297-y","url":null,"abstract":"<div><p>A new form of the equation of state (EOS) is considered to develop a model for describing the interior of a static, spherically symmetric, compact anisotropic star. The analytic solution is obtained using the Finch and Skea ansatz for the metric potential <span>(g_{rr},)</span> with a distinct geometric interpretation for the related background spacetime. The model parameters are fixed by matching the interior solution to the Schwarzschild exterior metric over the boundary of the star, together with the requirement that the radial pressure vanishes at the boundary. Data available for the pulsar 4<i>U</i>1802030 has been utilized to analyze the physical viability of the developed model. The model is shown to be stable.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 2","pages":"741 - 750"},"PeriodicalIF":1.6,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141947675","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":"Effect of deposition cycle and annealing on the structural, optical, electrical, and photoluminescence properties of SnS films obtained from rapid S-SILAR technique","authors":"Pawan Kumar,&nbsp;Gowrish K. Rao","doi":"10.1007/s12648-024-03349-3","DOIUrl":"10.1007/s12648-024-03349-3","url":null,"abstract":"<div><p>In this paper, we present an optimized procedure for depositing SnS thin films using the rapid S-SILAR technique. We also analyze the effects of deposition cycles and post-deposition annealing on various film properties. XRD analysis indicates the presence of orthorhombic and cubic phases in the films. Energy dispersive X-ray analysis confirms near-optimal stoichiometry. SEM images depict the growth of closely spaced spherical granules. High optical absorption is observed in the mid-visible to NIR region, with the absorption edge shifting towards the NIR region after annealing. The bandgap values range from 1.6 eV to 1.9 eV, which is ideal for photovoltaic applications. PL spectra show three clusters of peaks corresponding to red and green emissions. Hall measurements confirm that both the as-deposited and annealed SnS films exhibit p-type conductivity, with a hole concentration on the order of 10¹⁵ cm⁻³.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"1007 - 1019"},"PeriodicalIF":1.6,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12648-024-03349-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141947676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Obliquely nonlinear solitary waves in magnetized electron–positron–ion plasma","authors":"L. Nazziwa,&nbsp;I. Habumugisha,&nbsp;E. Jurua","doi":"10.1007/s12648-024-03329-7","DOIUrl":"10.1007/s12648-024-03329-7","url":null,"abstract":"<div><p>This study focused on nonlinear ion-acoustic solitary structures (IASS) in a magnetized plasma system that is kappa distributed comprising electrons, positrons, and ions (e–p–i) using a fluid theory approach. A novel nonlinear inverse dispersion relation peculiar to this complex plasma environment was derived. The dispersive properties of ion-acoustic waves in magnetized e–p–i plasma environment were investigated considering the influence of various superthermal of electrons and positrons <span>((kappa _{e}~textrm{and} ~kappa _{p}))</span>, unperturbed positron to ion density ratio, <i>p</i>, electron to ion density ratio, <span>((delta ))</span>, ion to electron temperature ratio, <span>((sigma ))</span>. By numerically analyzing the impact of plasma properties, particularly the nonlinear dispersion characteristics in a magnetized e–p–i plasma. The influence of the external magnetic field (obliqueness) angle, <span>(theta)</span>, which alters the frequency value of <span>((omega ^{2}))</span>. It was found that the values of <span>(delta)</span>, the frequency <span>(omega ^{2})</span> of IASS waves decreases with increasing <span>(delta)</span>. This result has significant implications for understanding the dynamics of various astrophysical settings, such as the solar wind. However, when <span>(delta &gt; 0)</span>, the curves become more nonlinear, indicating the waves become more dispersive. Further, it is discovered that as the value of <span>(theta)</span> for <span>(+~omega ^{2})</span> solution increases, the shape of the dispersion curve does not significantly change. In contrast, it is observed from the <span>(-~omega ^{2})</span> solution that for all values of angle <span>(theta)</span>, frequency decreases with increasing angle <span>(theta)</span>. This is because the ion-acoustic mode is strong at the propagation angle at <span>(theta = 0^{circ })</span> and weakens as the propagation angle increases, eventually disappearing at <span>(theta = 90^{circ })</span>. Thus, these findings provide an appreciable understanding of the dispersion characteristics of obliquely propagating IASS modes in a magnetized e–p–i plasma. In conclusion, our results provide important and new information on the interaction of plasma parameters in complex astronomical (natural) and laboratory (artificial) settings.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"1193 - 1204"},"PeriodicalIF":1.6,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141947804","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":"Effect of heat treatment on structural, optical and magneto-dielectric properties of Co–Cu spinel nano ferrites","authors":"Poorva Rani,&nbsp;Priyanka Godara,&nbsp;Ram Mehar Singh,&nbsp;Ashok Kumar","doi":"10.1007/s12648-024-03283-4","DOIUrl":"10.1007/s12648-024-03283-4","url":null,"abstract":"<div><p>Here, we have investigated the impact of heat treatment on structural, morphological, optical and magneto-dielectric properties of Co_0.5Cu_0.5Fe₂O₄ spinel nanoferrites prepared by sol–gel auto-combustion method. The prepared samples were sintered at 700, 800, and 900 °C and then characterized by XRD, FTIR, SEM, UV–Vis spectroscopy, VSM and impedance analyser techniques. The obtained XRD patterns were refined with Full Prof Suite Software which confirmed the cubic spinel structure of the prepared sample and it was observed that crystallite size increases from 38 to 44 m with increase in sintering temperature and the same is confirmed by W–H plot also. The SEM micro graphs represent the morphological features of the prepared samples and average particle size was calculated by using the imageJ software, which ranges 47–126 nm with increase in temperature. The FTIR spectra confirmed the presence of tetrahedral and octahedral sites in the prepared samples. Various optical parameters were recorded using UV–Vis spectroscopy and it was found that optical band gap energy decreased from 3.976 to 3.832 eV, whereas refractive index increased from 2.262 to 2.283, and high frequency dielectric constant varied from 5.114 to 5.210 with rise in temperature which was due to decrease in grain boundary area and porosity. The magnetic studies were carried out at room temperature using VSM and it was found that magnetic parameters get improved with increase in sintering temperature. Dielectric measurements were made by impedance analyser in a frequency range of 20 Hz to 10 MHz which were in consonance with Maxwell–Wagner polarization and Koop’s theory.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 2","pages":"425 - 441"},"PeriodicalIF":1.6,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864290","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":"Structural and optical properties of Cu:CdS thin films on soft polymer substrate","authors":"Sk. Faruque Ahmed,&nbsp;Mohibul Khan","doi":"10.1007/s12648-024-03344-8","DOIUrl":"10.1007/s12648-024-03344-8","url":null,"abstract":"<div><p>The structural and optical properties of copper doped cadmium sulfide (Cu:CdS) thin films on flexible polyethylene terepthalate substrates have been presented. The hexagonal crystallite structure of as-deposited thin films was characterized by the X-ray diffraction technique. X-ray photoelectron spectroscopy has been used to study the chemical binding energy and compositional analysis of the deposited thin films. The surface morphology of the deposited thin films has been analysed by an atomic force microscope image. The optical and photoluminescence properties of deposited films have been studied by UV–Vis–NIR spectrophotometer and fluorimeter respectively. A linear shrinkage of lattice parameters has been observed in the CdS thin films with Cu doping because of the smaller ionic radius of Cu than that of Cd. The optical band gap energy of CdS thin films decreased initially with Cu doping due to s, p–d exchange interactions and then increased due to the reduction in crystallite size. The photoluminescence property of the Cu:CdS thin films has been studied at room temperature (30 °C). Photoluminescence spectra showed two emission peaks around 545 nm and 580 nm, respectively, the exact positions of which are dependent on the Cu at% in the thin films. The former is due to the band-band transition of CdS, and the second is due to sulphur vacancy.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"987 - 995"},"PeriodicalIF":1.6,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864292","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":"Performance enhancement of FASnI3 perovskite photovoltaic cell through gradient re-arrangement of bulk defect and distinct charge transport layers","authors":"Ramadevi Janapaneni,&nbsp;Deboraj Muchahary","doi":"10.1007/s12648-024-03350-w","DOIUrl":"10.1007/s12648-024-03350-w","url":null,"abstract":"<div><p>This work deals with theoretical analysis of performance of a formamidinium tin iodide (FASnI₃) based perovskite solar cell. The advantages of using FASnI₃ over other perovskites include its low toxicity and environmental friendliness. While FASnI₃ has slightly lower thermal and moisture stability compared to the inorganic CsSnI₃, it offers better tunability of properties and higher power conversion efficiency (CE) potential. In PVSCs not only the surface defect but also the high concentration of Sn⁴⁺ creates huge bulk defect density inside the FASnI₃ and limits the CE. The bulk defect is of two types (1) fixed ionic defects due to Sn⁴⁺ and (2) mobile ionic defects due to Sn interstitial and halide vacancy. With a goal to overcome the impact of fixed defect, we used a technique to gradient distribution of Sn⁴⁺ mediated bulk defects inside the absorber. The PVSC: ITO/PEDOT: PSS/FASnI₃/C60/Au is simulated in OghmaNano where uniform distribution versus gradient distribution of defect inside FASnI₃ are analyzed. The ~ 10 to 13% rise in CE is observed for the gradient distribution of defect and is attributed to the enhancement in electric field inside the device. Moreover, the impact of mobile ions on the performance of both uniform and gradient PVSCs is comprehensively analyzed and reported in this work. The analysis indicates that an ion density up to the order of 10²² m⁻³ has no significant impact on the performance of the PVSC. In addition, considering the pivotal role of charge transport layers, seven different materials such as MoO₃, PEDOT: PSS, TCTA, V₂O₅, Li_0.05Ni_0.95O, SrCu₂O₂, and CuI are assessed for eligibility as HTAL in the proposed PVSC. Amongst those the CuI and C60 as HTAL and ETAL results in highest CE, FF, J_SC and V_OC of 20.64%, 69.09%, 1.14 V and 26.16 mA cm⁻² respectively. The reported photovoltaic device with high CE is environment friendly and may be a potential candidate for solar energy harvesting.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"1021 - 1031"},"PeriodicalIF":1.6,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872962","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":"Energy levels, wavelengths, transition probabilities, weighted oscillator strengths, and line strengths for carbon-like ions with Z = 21–30","authors":"W. Tang,&nbsp;B. L. Deng,&nbsp;G. S. Zhang,&nbsp;B. Meng,&nbsp;R. Yang,&nbsp;S. Wang","doi":"10.1007/s12648-024-03324-y","DOIUrl":"10.1007/s12648-024-03324-y","url":null,"abstract":"<div><p>In this study, the energy levels (<i>E</i>), lifetimes (<i>τ</i>), wavelengths (<i>λ</i>), transition probabilities (<i>A</i>), weighted oscillator strengths (<i>gf</i>) and line strengths (<i>S</i>) among the (1<i>s</i>²)2<i>s</i>²2<i>p</i>², 2<i>s</i>²2<i>p</i>3<i>s</i>, 2<i>s</i>²2<i>p</i>3<i>d</i>, and 2<i>s</i>2<i>p</i>²3<i>p</i> configurations of carbon-like ions with <i>Z</i> = 21–30 were determined using the multiconfiguration Dirac–Hartree–Fock (MCDHF) method. We confirmed the reliability of the energy levels by comparing them with the results of other theoretical methods and experimental observations. The present wavelengths for C-like ions were in good agreement with the previous experimental and theoretical results, with most wavelength differences below 0.8%. Based on the relative deviation (<i>dT</i>) and line strengths (<i>S</i>), respectively, we estimated the uncertainty of the computed transition data. Out of the 1300 transitions computed in this work, 1207 (699) have uncertainties fewer than or equal to 7% as determined by <i>dT</i> (<i>S</i>). We hope these data will be utilized to expand the C-like ion database and provide reference information for experimental studies in plasma experiments.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"793 - 870"},"PeriodicalIF":1.6,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864293","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":"Onset of identical synchronization in the spatial evolution of optical power in a waveguide coupler","authors":"Jyoti Prasad Deka","doi":"10.1007/s12648-024-03348-4","DOIUrl":"10.1007/s12648-024-03348-4","url":null,"abstract":"<div><p>In this work, we investigated the spatial evolution of optical power in a closed-form optical waveguide configuration consisting of six passive waveguides and each of the waveguides exhibits equal strength of Kerr nonlinearity. We considered only nearest neighbor interaction between the waveguides. We found that in the case of low Kerr nonlinearity, spatial evolution of optical power shows identical synchronization. But when we increased the strength of Kerr nonlinearity, we discovered that spatial evolution of optical power in all waveguides exhibits independent characteristics. On the other hand, we have studied the impact of the coupling constant on the synchronization dynamics of our system. Our findings showed us that strong coupling can strengthen the collective dynamics in the presence of strong Kerr nonlinearity. From our results, we can conclude that Kerr nonlinearity in our system plays the role of disorder parameter that destroys as well as alters the synchronization behavior of evolution of optical power in the waveguides and coupling constant, on the other hand, plays the role of an antagonist and restores synchronization in the model.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"1071 - 1076"},"PeriodicalIF":1.6,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776772","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":"A DFT approach on the investigations of the structural and optoelectronic properties of lead-free and Ge-based mixed halide perovskites RbGeBr2Cl and RbGeI2Cl","authors":"Hameed T. Abdulla","doi":"10.1007/s12648-024-03354-6","DOIUrl":"10.1007/s12648-024-03354-6","url":null,"abstract":"<div><p>In this study, the structural, electronic and optical properties of the tetragonal-phase of the free-lead mixed halides perovskites RbGeI₂Cl and RbGeBr₂Cl are investigated. These materials have raised an interest due to their enhanced electronic and optical properties, demonstrated by high charge carrier mobility and adjustable band gap. The calculations employed ab-initio methods, predominantly based on the density functional theory (DFT), the exchange–correlation functional is processed with the generalized gradient approximation (GGA) approach which uses a ‘flavour’ of the Perdew Burke Ernzerhof (PBE). The DFT framework allows to study the structural parameters, band structure, and density of states (DOS). The calculations of the band structure show that RbGeI₂Cl and RbGeBr₂Cl have a direct band gap. In addition, the dielectric function and absorption coefficient as part of the investigation into the optical properties of these perovskites are calculated. The obtained results suggest that the two studied mixed halide perovskites have the capability to absorb electromagnetic radiation outside the visible spectrum, making them a promising candidate for potential uses in optoelectronic applications within the ultraviolet (UV) range.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 3","pages":"1041 - 1050"},"PeriodicalIF":1.6,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776769","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}