Indian Journal of Physics最新文献

{"title":"Unravelling the effect of Cr doping on electronic transport properties of barium calcium titanate ceramics","authors":"Lalita,&nbsp;Preeti Redhu,&nbsp;Sonia Ahlawat,&nbsp;Suman Pawaria,&nbsp;Preeti Sharma","doi":"10.1007/s12648-024-03455-2","DOIUrl":"10.1007/s12648-024-03455-2","url":null,"abstract":"<div><p>The present paper investigates effect of Cr doping on AC conductivity, electric modulus and impedance spectroscopy on Barium Calcium Titanate ceramics synthesized by standard solid state reaction method in the frequency range 100 Hz-1 MHz from 633 to 773 K. With increase in Cr content frequency dependent AC conductivity show mixed behavior and found to obey Almond-West Law. Various parameters viz. σ_dc, ω_H and s have been extracted from the fitting of <span>({sigma }{prime}left(omega right))</span> with Almond West Law. Conduction mechanism in studied ceramics has been determined by analyzing frequency exponent and found that conduction occurs via Overlapping Large-Polaron Tunnelling. The activation energy for DC conduction lies between 0.72 and 0.53 eV. Relaxation time and activation energy for dielectric relaxation determined from fitting of imaginary part of electric modulus is in the range of 3.47 μs to 190.56 μs and 0.99 to 0.74 eV respectively. Nyquist plots consist of two combined semicircles, signifying the simultaneous involvement of both grain and grain boundaries in the high and low-frequency regions and are fitted with a series combination of two R-CPE equivalent circuits indicating non-Debye type relaxation. Both grain and grain boundaries resistances estimated from fitting of Nyquist’s plots using equivalent circuits are found to decrease with temperature indicating the semiconducting nature of the studied ceramic samples.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2105 - 2114"},"PeriodicalIF":1.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938673","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":"Novel soliton solutions of liquid drop model appear in fluid dynamics and modulation instability of dynamical system","authors":"U. Asghar,&nbsp;D. Chou,&nbsp;M. I. Asjad,&nbsp;S. A. O. Abdallah","doi":"10.1007/s12648-024-03441-8","DOIUrl":"10.1007/s12648-024-03441-8","url":null,"abstract":"<div><p>The main concern of this manuscript is to investigate the function of dispersion within the formation of patterns in liquid drops described in the generalized (2+1)-dimensional Camassa–Holm–Kadomtsev–Petviashvili equation. The study incorporates the dynamics of molecular movement in liquids and the displacement of particles due to evaporation, leading to diverse cracking patterns observed in dried colloidal deposits. The considered model is particularly significant due to its ability to describe complex wave phenomena in multidimensional systems, making it highly relevant for understanding pattern formation in liquid systems. The technique includes the movement of molecules within a liquid and the displacement of particles brought on by evaporation. A method known as the Sardar sub-equation method is applied to find a new soliton solution of the Camassa–Holm–Kadomtsev–Petviashvili model. The obtained results are in the form of bright (non-topological) solitary or bell-shaped and dark (topological/smooth) solitary or anti-bell-shape soliton solutions. The newly derived soliton solutions offer valuable insights into the behavior of solitary waves under dispersion effects and contribute to a deeper understanding of the pattern formation process. To see the physical insights of the obtained solutions, various graphical representations are utilized, as well as three-dimensional, two-dimensional, and contour plots plus density plots. Further, the outcomes obtained are compared with the existing literature for a better understanding. The importance of these solutions lies in their potential to enhance the accuracy of predictive models for liquid drop dynamics and colloidal deposition processes. Additionally, modulational instability is also discussed, for small versions, a set of resonances occurs in the gain spectrum. It is a crucial concept in the study of nonlinear wave dynamics, offering insights into wave behavior, pattern formation, and energy localization. Lastly, the proposed method is expected to provide a significant enhancement.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2151 - 2164"},"PeriodicalIF":1.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938591","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 chromium (Cr2+) additive on electrical and dielectric studies of cobalt doped cadmium–nickel perminvar ferrite","authors":"Shamsun Alam,&nbsp;H. N. Das,&nbsp;Salahuddin Sourav","doi":"10.1007/s12648-024-03450-7","DOIUrl":"10.1007/s12648-024-03450-7","url":null,"abstract":"<div><p>This study examined the impact of cobalt-doped cadmium–nickel perminvar ferrite on the electrical and dielectric properties of chromium (Cr²⁺) additions. The two-stage sintering ceramic process was used to manufacture the polycrystalline ferrite samples with compositions of Co_0.02Cd_0.2+xNi_0.58−xFe_2.2O₄ (x = 0.08) and Co_0.02Cd_0.28Ni_0.5Cr_0.2Fe₂O₄. The electric behavior of all perminvar ferrites was presented by measuring temperature-dependent resistivity and frequency-dependent resistivity. At 30 °C, the Cr-doped sample had a DC resistivity (ρ_dc) of 502.12 Ω-cm, which was much higher than the non-doped samples. This suggests that Cr²⁺ addition leads to increased resistivity. At 1 kHz, the Cr-doped sample has an AC resistivity (ρ_ac) of 4644.28 Ω-cm, indicating higher resistance due to Cr doping. The difference in DC and AC resistivity is due to the material’s different conduction methods and frequency responsiveness. The findings indicate that introducing Cr improves the material’s electrical resistivity and dielectric characteristics, making it ideal for high-frequency applications and devices with low energy loss. Variations of dielectric constant and dielectric loss with frequency and temperature had also been studied. The change in DC resistivity displayed a decreasing pattern with the increase in temperature and was found to be almost constant up to a specific temperature and then almost unchanged. To study the pattern of dielectric properties, dielectric constant (<i>ε</i>′), dissipation factor (tan<span>(delta )</span>), and dielectric loss (<i>ε</i>″) were graphed with temperature. These behaviors exhibited a decreasing pattern with the initial rise of temperature and then increased steeply until reaching a dielectric transition temperature. Frequency-dependent ac resistivity, dielectric constant, and dielectric loss of all ferrites decline with the rise in frequency, which exhibits conventional ferrimagnetic behavior. These properties showed that dispersion was because of Maxwell–Wagner kind of space charge interfacial polarization in fulfillment of Koop’s two-layer model.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2077 - 2085"},"PeriodicalIF":1.6,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938532","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":"La3+ doping impact on CdCe0.5Fe1.5-yLayO4 spinel ferrites properties and the correlation of crystallite size with magneto-dielectric parameters","authors":"R. Khan,&nbsp;M. H. H. Mahmoud,&nbsp;Islam H. El Azab,&nbsp;Zeinhom M. El-Bahy,&nbsp;A. U. Rahman","doi":"10.1007/s12648-024-03454-3","DOIUrl":"10.1007/s12648-024-03454-3","url":null,"abstract":"<div><p>This study explores the impact of La³⁺ doping on the structural, morphological, and magneto-dielectric properties of CdCe_0.5Fe_1.5-yLa_yO₄ (where y = 0.0, 0.01, 0.02, 0.03, and 0.04) spinel ferrites (SFs), with a particular focus on the correlation between crystallite size and magneto-dielectric parameters. The as-prepared SFs were synthesized via a sol–gel auto-ignition route. Different La³⁺ doping levels were introduced in the CdCe_0.5Fe_1.5-yLa_yO₄ spinel matrix and were analyzed the resulting structural, magnetic, and dielectric properties. X-ray diffraction studies revealed the change in crystallite size with increasing La³⁺ content. The surface morphology was observed using scanning electron microscopy analysis. Hysteresis loops were used to study the magnetic behavior and showed that increased La³⁺ doping significantly altered the magnetic properties. Dielectric studies indicated an improvement in dielectric constant and tangent loss, which are attributed to the enhanced polarization mechanisms due to La³⁺ doping. The correlation between crystallite size and magneto-dielectric properties was explored, revealing significant dependencies that provide insights into optimizing as-prepared SFs for advanced technological applications. The study demonstrates the effectiveness of La³⁺ doping in tailoring the magneto-dielectric response, and La³⁺ doped Cd-Ce SFs enhanced performance indicates that it is a good candidate for electronic and magnetic device applications.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2093 - 2103"},"PeriodicalIF":1.6,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938533","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":"Analysis and implementation of the equivalent load circuit for switching performance of hot cathode plasma switch developed","authors":"Akhilesh Mishra,&nbsp;Ram Prakash Lamba,&nbsp;Bharat Lal Meena,&nbsp;Abhijit Ravindra Tillu,&nbsp;Udit Narayan Pal","doi":"10.1007/s12648-024-03448-1","DOIUrl":"10.1007/s12648-024-03448-1","url":null,"abstract":"<div><p>The manuscript is focused on the equivalent load circuit physics for the switching performance of the 35 kV/1–8 kA sealed-off high current hot cathode plasma switch developed for the fast pulsed power applications in the recent scientific and industrial field. In this paper, physical interpretation of the equivalent circuit and the method to reduce the load inductance in the discharge path have been discussed, which are essential to achieve the high peak discharge current with lesser reverse current during the switching operation. Further, low inductive coaxial load circuit analysis has been done and almost ~ 50% reduction in the load inductance is estimated. Consequently, the discharge circuit arrangement has helped to increase the peak current by ~ 10% and also reduce the reverse current by ~ 50%. This low inductive coaxial load has been used to draw the maximum discharge peak current of ~ 8 kA at ~ 33 kV applied voltage during switching. For this, the cathode and reservoir supply currents was optimized ~ 17.5 A and ~ 5.5 A, respectively. This analysis would be very much useful for the design and development of high-power hot cathode plasma switch (Thyratron) with low reverse current for fast pulsed power applications.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2307 - 2315"},"PeriodicalIF":1.6,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938502","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":"An inter-comparison between calculated solid angle for different geometrical correlations of source-detector through analytical and Monte Carlo approaches","authors":"Hamid Reza Baghani,&nbsp;Behzad Aminafshar","doi":"10.1007/s12648-024-03453-4","DOIUrl":"10.1007/s12648-024-03453-4","url":null,"abstract":"<div><p>Calculation of solid angle (Ω) is of particular importance in radiation detection purposes. Nevertheless, determining the Ω value by analytical methods is a difficult procedure in complicated geometry conditions. The current study evaluates the capability of the Monte Carlo simulation approach in Ω calculation at different geometrical correlations between the source and detector by comparing the obtained results with those of the analytical method. Ω values were calculated for four different geometrical correlations between the source and detector (point and disk source/circular and rectangular detector apertures) through both analytical (Ω_th) and Monte Carlo simulation (Ω_sim) approaches. The MCNPX code was used for Monte Carlo-based calculations. For all studied geometrical correlations, a good agreement was observed between Ω_th and Ω_sim values such that the maximum difference between the results was less than 4%. A better accordance between Ω_th and Ω_sim was found for a point source in comparison with the disk source. Finally, it is concluded that Monte Carlo simulation can be considered a fast and reliable alternative to the analytical method in determining the solid angle for a radiation detector, especially in complicated geometry conditions, where applying the analytical approach may fail to result in an accurate Ω value.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2207 - 2215"},"PeriodicalIF":1.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938395","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":"Ab initio and experimental investigations of the electronic and optical properties of pure and p-Aminopyridine-intercalated In1.2Ga0.8S3","authors":"Z. A. Jahangirli,&nbsp;S. G. Asadullayeva,&nbsp;I. R. Amiraslanov,&nbsp;Q. Y. Eyyubov,&nbsp;A. B. Rahimli,&nbsp;A. S. Abiyev","doi":"10.1007/s12648-024-03452-5","DOIUrl":"10.1007/s12648-024-03452-5","url":null,"abstract":"<div><p>The electronic and optical properties of pure and <i>p</i>-Aminopyridine-intercalated In_1.2Ga_0.8S₃ crystals were investigated using absorption and photoluminescence spectroscopy, and density functional theory. From the first principles calculation, we determined the band gap energy, nature of the chemical bonds, and dielectric functions of In_1.2Ga_0.8S₃. Band structure calculations reveal that the valence band maximum (VBM) and conduction band minimum (CBM) are both located at the high-symmetry point Γ, indicating that In_1.2Ga_0.8S₃ is a direct-gap semiconductor with a band gap of approximately 2.35 eV. From the projected density of states analysis, it is evident that the VBM primarily originates from the p-states of the S atom, while the CBM is mainly derived from the s-states of the Ga, In1, and In2 atoms. Furthermore, there is strong hybridization between the s- and p-states of the Ga atom and the s- and p-states of the In1 atom, respectively. The optical absorption and photoluminescence spectra of pure (unintercalated) and intercalated crystals were investigated experimentally at various temperatures. A significant increase in luminescence intensity was observed in the intercalated crystals. The absorption spectra indicate that intercalation with <i>p</i>-Aminopyridine increases the band gap by 0.14 eV compared to the pure crystal. Additionally, photoluminescence measurements show that the luminescence intensity of the intercalated compound is higher than that of the pure compound.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2087 - 2092"},"PeriodicalIF":1.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938396","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":"BICs supported by different polarized light in notched silicon nanorods metasurface","authors":"Q. Wu,&nbsp;J. Ma,&nbsp;S. Wu","doi":"10.1007/s12648-024-03438-3","DOIUrl":"10.1007/s12648-024-03438-3","url":null,"abstract":"<div><p>Symmetry-protected bound states in the continuum (BICs) are the eigenstates with forbidden radiation lying in the radiation continuum due to the symmetry incompatibility. When the symmetry is broken, BICs are transformed into quasi-BICs (Q-BICs) with an ultra-high quality factor. Typically, notches are created by adding or removing portions of dielectric nanostructures in a certain direction. This results in structures that only support Q-BICs excited by specific polarized light. In this work, we introduce a metasurface composed of bevelled double silicon nanorods, which supports the Q-BICs excited by not only y-polarized but also x-polarized incident light. Analysis from multipole decompositions and electromagnetic fields distributions confirm that the dominant contributions to the quasi-BICs under y-polarization are the toroidal dipole moment and magnetic quadrupole. The quasi-BICs under x-polarization are dominated by magnetic dipole and electric quadrupole. Our results may provide a route for enhance light–matter interaction, such as lasing, switching, nonlinear optics, and so on.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2257 - 2262"},"PeriodicalIF":1.6,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938202","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":"Thermodynamic equation of state of magnetized PNJL model of (2+1) flavor at finite baryonic density","authors":"S. Somorendro Singh","doi":"10.1007/s12648-024-03435-6","DOIUrl":"10.1007/s12648-024-03435-6","url":null,"abstract":"<div><p>Our recent research work for 2 flavor magnetized PNJL model has been extended to <span>(2+1)</span> flavor quarks cooperating the finite baryonic potential in the thermal mass and magnetic field in the potential of the Lagrangian density. The evaluation of equation of state and its relevant thermodynamic properties after incorporating the finite chemical potential in the thermal mass and magnetic field in the potential are represented in the results. The results show that all the thermodynamic parameters are found to be improved by the inclusion of the finite baryonic chemical potential. The result at the finite baryonic density also conforms and improves from our earlier work without the value of baryonic chemical potential. It means that there is an up-gradation in the outputs as predicted by the presence of baryonic chemical potential in the thermal mass.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2181 - 2190"},"PeriodicalIF":1.6,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938531","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":"f(R)-gravity and spacetimes with pseudo-projective curvature","authors":"Samrat Hossain,&nbsp;Dipankar Hazra,&nbsp;Avijit Sarkar","doi":"10.1007/s12648-024-03440-9","DOIUrl":"10.1007/s12648-024-03440-9","url":null,"abstract":"<div><p>One of the goals of the present article is to prove that a Lorentzian manifold is of constant curvature if and only if its pseudo-projective curvature tensor vanishes. It has been established that a conformally flat pseudo-projectively recurrent spacetime is a perfect fluid spacetime. As a consequence, it has been shown that such a spacetime represents a dust matter fluid, stiff matter and dark energy era under certain restrictions on the Ricci curvature. A conformally flat pseudo-projective recurrent spacetime has been analyzed in the perspective of <span>(fleft( Rright))</span>-gravity theory. For the model <span>(fleft( Rright) = ln left( aRright) +aexp left( -dfrac{R}{a}right))</span>, several energy conditions in terms of the Ricci curvature have been examined and, in addition, it has been shown that the Universe is in accelerating phase which satisfies the weak, null, dominant, and strong energy conditions.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 6","pages":"2331 - 2337"},"PeriodicalIF":1.6,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938705","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}