Indian Journal of Physics最新文献

{"title":"Inquisition on charge correlated multiferroic properties of La0.85Ce0.15FeO3 and La0.65Zn0.35FeO3 suitable for new functional device applications: a comparative study","authors":"G. Gowri,&nbsp;J. Mangaiyarkkarasi,&nbsp;S. Sasikumar","doi":"10.1007/s12648-026-04084-7","DOIUrl":"10.1007/s12648-026-04084-7","url":null,"abstract":"<div><p>The multiferroics cerium substituted La_0.85Ce_0.15FeO₃ (LCFO) and zinc substituted La_0.65Zn_0.35FeO₃ (LZFO) have been prepared by high -temperature solid state reaction route and their structures have been analyzed using XRD and Rietveld refinement techniques. MEM derived charge density study shows that LZFO has slightly high charge density as 0.6593 e/ų and 0.9108 e/ų along the Fe-O1 and La-O1 bonds than LCFO. LZFO contains small grains and particles with size of about 28 nm and 0.85 µm respectively. The band gap for LZFO multiferroic is found low as 2.12 eV. Both samples exhibit an exchange bias effect that causes its magnetic hysteresis curve to move in a negative direction, demonstrating the coexistence of two distinct magnetically ordered domains (AFM and FM). LZFO has low dielectric constant (807) and its ac conductivity is found as high as 2.68 × 10^–3 Ω⁻¹ m⁻¹. The values of electric polarization (P_m) and remanent polarization (P_r) are found to be relatively high (P_m = 39.19 µC/cm² and P_r = 39.02 µC/cm²) for LZFO than LCFO due to high leakage current. So far, no comparative study has been reported in the literature for Ce- doped LaFeO₃ and Zn- doped LaFeO₃, even for a single composition. In this article, the physical properties of La_0.85Ce_0.15FeO₃ and La_0.65Zn_0.35FeO₃ have been compared and correlated with charge density, which has not yet been explored in the literature. The effects of secondary (impurity) phase on the magnetic and electric properties are also discussed in this work, which were not addressed in our earlier studies.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 10","pages":"4183 - 4196"},"PeriodicalIF":1.7,"publicationDate":"2026-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909785","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 comparative investigation of band-gap engineering in BaZrS3 via Ti, Sn, Ca, Sr, and Se doping","authors":"T. Jothika,&nbsp;S. R. Meher","doi":"10.1007/s12648-026-04072-x","DOIUrl":"10.1007/s12648-026-04072-x","url":null,"abstract":"<div><p>BaZrS₃ is a promising absorber material for photovoltaic applications owing to its direct band gap, high absorption coefficient and excellent thermal and chemical stability. However, a comprehensive and consistent comparative assessment of Ti, Sn, Ca, Sr and Se doping effects using a unified computational framework is still needed. In this work, we systematically investigate the structural, electronic and optical properties together with formation energies and charge-density characteristics of Ti, Sn, Ca, Sr and Se doped BaZrS₃ using first-principles density functional theory (DFT) calculations within the <span>(DFT+U)</span> formalism. Doping is introduced by substituting Ba with Ca or Sr, Zr with Ti or Sn at a concentration of <span>(25,%)</span> and S with Se at a concentration of <span>(8.3,%)</span> within the unit cell. Structural analysis reveals dopant dependent lattice expansion or contraction accompanied by local structural distortions. The calculated formation energies provide insight into the relative stability and feasibility of dopant incorporation within the <span>(hbox {BaZrS}_3)</span> lattice. By comparing aliovalent and isovalent substitutions at different crystallographic sites, we identify a clear orbital-selective band-edge control mechanism in BaZrS₃, wherein Zr-site dopants govern the conduction band minimum, anion substitution modulates the valence band maximum and Ba-site substitutions remain electronically inert. Optical property analysis indicates that Ti and Sn doped systems exhibit a redshift in the absorption onset with enhanced visible light absorption compared to other dopants. Furthermore, charge density analysis at the valence band maximum and conduction band minimum elucidates the orbital contributions and bonding characteristics in both pristine and doped BaZrS₃. Overall, this study identifies Ti, Sn and Se doping as particularly promising strategies for tuning BaZrS₃ towards an optimal band gap range for photovoltaic applications.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 10","pages":"4073 - 4091"},"PeriodicalIF":1.7,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909759","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 spatiotemporal nonlocal fractional thermoelastic model with two-temperature and dual-phase-lag effects in non-simple media","authors":"M. E. Nasr,&nbsp;Ahmed E. Abouelregal,&nbsp;A. Soleiman,&nbsp;K. M. Khalil,&nbsp;Hamid M. Sedighi","doi":"10.1007/s12648-026-04061-0","DOIUrl":"10.1007/s12648-026-04061-0","url":null,"abstract":"<div><p>This study presents a unified theoretical framework for modeling thermoelastic behavior in materials at the micro- and nanoscale. The formulation combines four key components within a single model: spatio-temporal nonlocal elasticity, fractional-time derivatives with non-singular memory kernels of the Caputo–Fabrizio and Atangana–Baleanu types, dual-phase-lag heat conduction, and the two-temperature theory. The resulting framework extends higher-grade thermoelasticity by incorporating long-range spatial interactions, smooth temporal memory effects, finite thermal propagation speeds introduced by phase lags, and the distinction between the conductive and thermodynamic temperatures. To examine the implications of this formulation, we analyzed the dynamic response of an isotropic thermo-mechanical solid subjected to pulsed laser heating and a time-decaying mechanical load. The governing equations were solved numerically, enabling a systematic investigation of the effects of nonlocal parameters, the fractional order of the time derivatives, the temperature discrepancy between the conductive and thermodynamic temperature fields, and relaxation times on temperature, displacement, and stress distributions. The results indicate that the model yields temperature profiles consistent with benchmark numerical solutions reported in earlier studies, while producing responses that differ from those predicted by classical and various generalized thermoelastic theories. In particular, the inclusion of spatial nonlocality and fractional-time operators leads to smoother thermal and mechanical profiles, modifies wavefront propagation characteristics, and captures diffusion patterns associated with materials exhibiting size-dependent or anomalous behavior. The proposed framework provides a computationally manageable approach for studying coupled thermo-mechanical processes in small-scale systems, such as laser–material interactions, nanoscale heat transport in semiconductor devices, and materials governed by non-Fourier heat conduction. It provides a basis for further analytical and numerical investigations in generalized thermoelasticity.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 9","pages":"3703 - 3729"},"PeriodicalIF":1.7,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750729","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":"Amplitude-parameter-induced versatile dual-modulation of nonlinearity and dispersion in inhomogeneous higher-order-effect optical fibers","authors":"Kui Huo","doi":"10.1007/s12648-026-04073-w","DOIUrl":"10.1007/s12648-026-04073-w","url":null,"abstract":"<div><p>This study focuses on flexible nonlinearity- and dispersion-modulated similaritons in optical fibers with higher-order effects, and investigates the propagation dynamics governed by the inhomogeneous higher-order nonlinear Schrödinger equation. By introducing amplitude parameters for nonlinearity and dispersion, we obtain generalized solution structures that enable versatile dual modulation of similaritons under the newly derived unified constraint conditions. Exact solutions for bright, dark, W-shaped, and rogue-wave similaritons are derived. Through illustrative examples, we demonstrate distinct control over the amplitude, background intensity, and trajectory of similaritons by tuning these amplitude parameters. The results provide a theoretical framework for understanding higher-order dispersion, self-steepening, and Raman scattering, and offer practical guidance for pulse shaping in fiber-optic communication systems.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 10","pages":"4337 - 4344"},"PeriodicalIF":1.7,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909758","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 isotropic strain on thermoelectric properties of NaYX (X = C, Ge) half-Heusler compounds","authors":"Savita Grewal,&nbsp;Abdulla Abdulsalam,&nbsp;Ranjan Kumar","doi":"10.1007/s12648-026-04069-6","DOIUrl":"10.1007/s12648-026-04069-6","url":null,"abstract":"<div><p>This work employed density functional and Boltzmann transport theory to methodically examine how tensile and compressive strain affected the properties of the half-Heusler (HH) compound NaYX (X = C, Ge), such as electronic structure, elastic characteristics, and phonon dispersion relation. We determined the elastic constants and phonon dispersion curves of NaYX (X = C, Ge). Elastic properties show the mechanical stability, and phonons with positive frequency show the dynamical stability under isotropic compressive as well as tensile isotropic strain. Calculated formation energies are negative under tensile as well as compressive strain for NaYC and NaYGe, also showing the stability of compounds. Calculations also revealed that applying isotropic strain affected the electronic structure and bandgap of NaYX (X = C, Ge). Computed maximum figure of merit p-type (n-type) of pure NaYC and NaYGe are 0.57(0.51) and 0.19(0.27) at 1200K, respectively. Lattice thermal conductivity is calculated using Slack’s equation. The relaxation time (τ) of charge carriers is calculated using the Deformation potential theory (DP). The maximum figure of merit (ZT_max) for NaYC HH alloy is 0.24 for p-type at -4% and 0.21 for n-type at -2% under compressive isotropic strain at 1200K. ZT_max for NaYGe is 0.37 for p-type and 0.27 for n-type at 6% under tensile isotropic strain at 1200K. It is observed that NaYGe compounds are efficient thermoelectric materials for high-temperature applications.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 9","pages":"3753 - 3766"},"PeriodicalIF":1.7,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750960","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":"Monte Carlo analysis of magnetic ordering and compensation behavior in a zigzag graphene-like nanoribbon","authors":"M. Mouhib,&nbsp;A. EL Fadl,&nbsp;S. Bri,&nbsp;M. D. Belrhiti,&nbsp;H. Mounir","doi":"10.1007/s12648-026-04083-8","DOIUrl":"10.1007/s12648-026-04083-8","url":null,"abstract":"<div><p>The predicted magnetic states at the zigzag edges of graphene make it a highly viable material for future spintronic devices. Here, by means of the Monte Carlo simulation, we report the critical behavior of a ferrimagnetic mixed spin (5/2, 3/2) zigzag graphene nanoribbon (ZGNR), featuring a core–shell structure. First, after analyzing briefly how the length and the width of the ribbon affect its critical behavior, we have computed the phase diagrams at the ground state (T = 0) to unveil the presence of distinct boundaries separating different stable spin configurations. Next, we have examined the effects of the exchange couplings (J_S, J_C) and the crystal fields (D_S, D_C) on the phase diagrams and the magnetic properties, yielding satisfactory outcomes. Notably, we have found that the shell and the core may undergo magnetic ordering at either distinct or similar blocking temperatures (T_B), depending on the specific J_S and J_C strengths. Finally, we have identified threshold values of the exchange couplings and crystal fields showing the compensation behavior with the possibility of the occurrence of two compensation temperatures.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 10","pages":"4171 - 4182"},"PeriodicalIF":1.7,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909688","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":"Time-dependent field-induced transport in a T-shaped triple quantum dot system","authors":"H. L. Guo,&nbsp;Q. Li,&nbsp;D. Ran,&nbsp;K. F. Chen,&nbsp;Z. L. He","doi":"10.1007/s12648-026-04086-5","DOIUrl":"10.1007/s12648-026-04086-5","url":null,"abstract":"<div><p>We investigate electron transport through a T-shaped triple quantum dot system subjected to a time-dependent external field. Using the time-dependent Green’s function method, we calculate the average current. Under field irradiation, the three main current peaks exhibit reduced intensity, accompanied by the emergence of photon-assisted sideband peaks in the current spectrum. As the field amplitude increases, the main peaks evolve differently: notably, the central peak can transition into a current valley. By tuning the field frequency, reversible conversion between current peaks and valleys is achieved. Moreover, adjusting the interdot coupling strength gives rise to narrow Fano-type current resonances, which broaden with increasing coupling and eventually evolve into conventional current peaks. The applied field also enables controlled switching between zero and finite current states, suggesting the feasibility of an optically controlled quantum switch. This work provides insights for the design of future nanoscale devices and their applications in quantum information processing.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 10","pages":"4197 - 4203"},"PeriodicalIF":1.7,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909689","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":"Logamediate expansion and dark-energy-driven acceleration in (fleft(Tright)) teleparallel gravity","authors":"Ather Husain,&nbsp;Shakeel Khan,&nbsp;Rishikumar Agrawal,&nbsp;Salim Shekh","doi":"10.1007/s12648-026-04065-w","DOIUrl":"10.1007/s12648-026-04065-w","url":null,"abstract":"<div><p>In this work, we analyse the accelerated expansion of the universe within the framework of telerparallel <span>(fleft(Tright))</span> gravity by adopting a logamediate form of the scale factor <span>(aleft(tright)={e}^{left[beta {left(text{l}text{n}tright)}^{alpha }right]})</span> in a spatially flat FRW geometry. Modified field equations corresponding to the power-law form <span>(fleft(Tright)={T}^{eta })</span> were derived and analyzed in detail. Using logarithm expansion, we examined the behavior of key cosmological quantities such as energy density, isotropic pressure, equation of state (EoS), stability factor, and energy conditions of the model. Our results show that the model successfully exhibits a transition from deceleration to acceleration and reproduces the radiation, quintessence, and phantom phases. The violation of the strong energy condition ensures late-time acceleration, whereas stability analysis reveals the dynamic nature of the model within the <span>(fleft(Tright))</span> framework.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 9","pages":"3971 - 3985"},"PeriodicalIF":1.7,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750655","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 implementation of high-rate quantum random number generation system","authors":"Mohammadreza Abazari,&nbsp;Majid Jaberi,&nbsp;Mina Farajzadeh,&nbsp;AmirHosein Dadahkhani,&nbsp;Seyed Ahmad Madani","doi":"10.1007/s12648-026-04068-7","DOIUrl":"10.1007/s12648-026-04068-7","url":null,"abstract":"<div><p>This paper presents a high-rate Quantum Random Number Generator (QRNG) combining a Zener diode-based QRNG with LFSR-based sampling and expansion. In the quantum tunneling regime, the Zener diode produces truly random analog signals, and LFSR circuits increase the final bit rate by expanding this entropy source. We obtain 520 Mbit/s without the need for offline processing by seeding the LFSR with the Zener output. The real-time SHA-256 hashing on a Zynq-7020 FPGA guarantees output stability and quality. This hybrid strategy provides a cost-effective solution that passes the ENT, Borel normality, and NIST tests by striking a balance between the statistical quality of real randomness and the speed of deterministic expansion.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 10","pages":"4425 - 4430"},"PeriodicalIF":1.7,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909660","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":"Exploring the role of effective nucleon–nucleon interactions in the 28Si(18O,16O)30Si reaction near-barrier","authors":"A. Hemmdan,&nbsp;Ghada G. El Deen M. Kandeel,&nbsp;Zakaria M. M. Mahmoud,&nbsp;M. A. Hassanain","doi":"10.1007/s12648-026-04085-6","DOIUrl":"10.1007/s12648-026-04085-6","url":null,"abstract":"<div><p>The two-neutron transfer reaction ²⁸Si(¹⁸O,¹⁶O)³⁰Si at 56 MeV, about 17 MeV above the Coulomb barrier(<span>(E_{B} approx 39.1)</span>)MeV, was investigated to explore the role of different nucleon–nucleon (<i>NN</i>) interactions on the transfer mechanisms within the framework of coupled reaction channels and coupled channels Born approximation models. Three effective <i>NN</i> interactions, namely; M3Y, SPP2, and JLM, were employed to construct the real and imaginary optical potentials. Elastic and inelastic scattering analyses were first performed to constrain the potential parameters, which showed that the JLM potential provides a better description at backward angles, whereas M3Y and SPP2 reproduce the data more accurately at forward scattering angles. The analysis of the transfer reaction channels was performed using extreme clusters, independent coordinate and sequential transfer mechanisms. In the ground and low-lying excited state transitions, M3Y and SPP2 provide comparable and generally good agreement with the experimental data compared to JLM, although the latter performs better in reproducing the full angular distribution for higher excited states. This study highlights the sensitivity of two-neutron transfer observables to the <i>NN</i> interaction choice and confirms the predominance of the sequential mechanism at the studied energy near the Coulomb barrier.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"100 10","pages":"4371 - 4381"},"PeriodicalIF":1.7,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909659","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}