We studied the magnetoresistance (MR) of well-characterized samples of CoFeSi at x=0.2, 0.4, and 0.65 at temperatures between 1.8 and 100 K and magnetic fields of 9 T. The quasilinear dependence of MR on the magnetic field at low temperatures and the practically isotropic properties of MR in these compounds are tentatively attributed to the specifics of Weyl electron spectra and general disorder of the materials.
{"title":"Isotropic and linear magnetoresistance of Co1−xFexSi at x=0.2; 0.4; 0.65","authors":"A.E. Petrova , S. Yu. Gavrilkin , V.A. Stepanov , S.S. Khasanov , Dirk Menzel , S.M. Stishov","doi":"10.1016/j.physb.2026.418334","DOIUrl":"10.1016/j.physb.2026.418334","url":null,"abstract":"<div><div>We studied the magnetoresistance (MR) of well-characterized samples of Co<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Fe<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>Si at x=0.2, 0.4, and 0.65 at temperatures between 1.8 and 100 K and magnetic fields of 9 T. The quasilinear dependence of MR on the magnetic field at low temperatures and the practically isotropic properties of MR in these compounds are tentatively attributed to the specifics of Weyl electron spectra and general disorder of the materials.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418334"},"PeriodicalIF":2.8,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-28DOI: 10.1016/j.physb.2026.418335
Shi-Chao Fang, Jing Fan, Xin-Yi Liao
An important topic in current research on high-temperature cuprate superconductors is understanding the relationship between charge order and superconductivity. We systematically study nematic charge correlations, spin correlations, and superconducting pairing correlations in the standard three-orbital Emery model using the ground-state constrained-path quantum Monte Carlo method. Our unbiased numerical simulations show that, in the charge-transfer energy regime , the nematic correlations exhibit different behaviors near the region of momentum space as the Coulomb repulsive interaction between the oxygen and orbitals increases, for the two cases and . Simultaneously, the spin correlations are enhanced, while the -wave pairing correlations are suppressed, in these two cases. Because the nematic correlations near the region exhibit completely different behaviors, and the -wave pairing correlations consistently weaken under the influence of the Coulomb repulsive interaction across different charge-transfer energy regimes, the relationship between nematic fluctuations and superconductivity cannot be determined from the above perspective. On the other hand, we introduce a new type of electronic interaction, the so-called off-site nematic interaction. The off-site nematic interaction mainly controls the fluctuations of nematic correlations near or , accompanied by a weakening of the pairing correlations. Our findings indicate that the nematic fluctuations strongly competes with superconductivity in the three-orbital Hubbard model of cuprate superconductors.
{"title":"Competition between nematic fluctuations and superconductivity in cuprate superconductors: Quantum Monte Carlo study of a three-orbital Hubbard model","authors":"Shi-Chao Fang, Jing Fan, Xin-Yi Liao","doi":"10.1016/j.physb.2026.418335","DOIUrl":"10.1016/j.physb.2026.418335","url":null,"abstract":"<div><div>An important topic in current research on high-temperature cuprate superconductors is understanding the relationship between charge order and superconductivity. We systematically study nematic charge correlations, spin correlations, and superconducting pairing correlations in the standard three-orbital Emery model using the ground-state constrained-path quantum Monte Carlo method. Our unbiased numerical simulations show that, in the charge-transfer energy regime <span><math><mrow><mi>ɛ</mi><mo>=</mo><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>−</mo><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>p</mi></mrow></msub></mrow></math></span>, the nematic correlations exhibit different behaviors near the <span><math><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>)</mo></mrow></math></span> region of momentum space as the Coulomb repulsive interaction <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>p</mi><mi>p</mi></mrow></msub></math></span> between the oxygen <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>x</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>y</mi></mrow></msub></math></span> orbitals increases, for the two cases <span><math><mrow><mi>ɛ</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>0</mn></mrow></math></span> and <span><math><mrow><mi>ɛ</mi><mo>=</mo><mn>3</mn><mo>.</mo><mn>0</mn></mrow></math></span>. Simultaneously, the spin correlations are enhanced, while the <span><math><mi>d</mi></math></span>-wave pairing correlations are suppressed, in these two cases. Because the nematic correlations near the <span><math><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>)</mo></mrow></math></span> region exhibit completely different behaviors, and the <span><math><mi>d</mi></math></span>-wave pairing correlations consistently weaken under the influence of the Coulomb repulsive interaction <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>p</mi><mi>p</mi></mrow></msub></math></span> across different charge-transfer energy regimes, the relationship between nematic fluctuations and superconductivity cannot be determined from the above perspective. On the other hand, we introduce a new type of electronic interaction, the so-called off-site nematic interaction. The off-site nematic interaction mainly controls the fluctuations of nematic correlations near <span><math><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>)</mo></mrow></math></span> or <span><math><mrow><mo>(</mo><mi>π</mi><mo>,</mo><mi>π</mi><mo>)</mo></mrow></math></span>, accompanied by a weakening of the pairing correlations. Our findings indicate that the nematic fluctuations strongly competes with superconductivity in the three-orbital Hubbard model of cuprate superconductors.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418335"},"PeriodicalIF":2.8,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-28DOI: 10.1016/j.physb.2026.418331
You Xie, Jiahao Wang, Zhengyong Chen, Yan Chen, Huaze Zhu, Tao Zhang
First-principles calculations systematically investigate the structural stability, electronic properties, and contact behavior of two-dimensional van der Waals heterostructures (vdWHs) composed of metallic VS2 (or VSe2) and semiconducting SiS2 monolayers. Both VS2/SiS2 and VSe2/SiS2 vdWHs exhibit excellent stability with low lattice mismatch and negative binding energy. VS2/SiS2 forms an n-type Schottky contact (barrier height of 0.38 eV), while VSe2/SiS2 shows a near-Ohmic contact (0.08 eV). Quantum tunneling reveals a significant interfacial barrier (∼4.5 % probability). Vertical strain and external electric fields effectively modulate the Schottky barrier height, tunneling probability, and metal-induced gap states. Compressive strain enhances interfacial coupling, while tensile strain suppresses it. Electric fields enable continuous, reversible contact tuning, even inducing Schottky-to-Ohmic transitions, with VSe2/SiS2 exhibiting greater tunability. This work provides insights and a design basis for tunable 2D electronic devices.
{"title":"Interface engineering of Schottky contacts in 2D VX2/SiS2 (X = S, Se) heterostructures via strain and electric field: manipulating barrier height and quantum tunneling behavior","authors":"You Xie, Jiahao Wang, Zhengyong Chen, Yan Chen, Huaze Zhu, Tao Zhang","doi":"10.1016/j.physb.2026.418331","DOIUrl":"10.1016/j.physb.2026.418331","url":null,"abstract":"<div><div>First-principles calculations systematically investigate the structural stability, electronic properties, and contact behavior of two-dimensional van der Waals heterostructures (vdWHs) composed of metallic VS<sub>2</sub> (or VSe<sub>2</sub>) and semiconducting SiS<sub>2</sub> monolayers. Both VS<sub>2</sub>/SiS<sub>2</sub> and VSe<sub>2</sub>/SiS<sub>2</sub> vdWHs exhibit excellent stability with low lattice mismatch and negative binding energy. VS<sub>2</sub>/SiS<sub>2</sub> forms an n-type Schottky contact (barrier height of 0.38 eV), while VSe<sub>2</sub>/SiS<sub>2</sub> shows a near-Ohmic contact (0.08 eV). Quantum tunneling reveals a significant interfacial barrier (∼4.5 % probability). Vertical strain and external electric fields effectively modulate the Schottky barrier height, tunneling probability, and metal-induced gap states. Compressive strain enhances interfacial coupling, while tensile strain suppresses it. Electric fields enable continuous, reversible contact tuning, even inducing Schottky-to-Ohmic transitions, with VSe<sub>2</sub>/SiS<sub>2</sub> exhibiting greater tunability. This work provides insights and a design basis for tunable 2D electronic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418331"},"PeriodicalIF":2.8,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-27DOI: 10.1016/j.physb.2026.418323
F.J.A. Santos , J.S. Jesus , R. Tartaglia , A.F. Lima
In this work, we employed spin-polarized density functional theory calculations to investigate the magnetic ordering, electronic structure, linear optical response, and photocatalytic activity of NiSb2O6 and NiTa2O6 in the trirutile crystal structure. The calculations were carried out using the GGA-PBEsol functional, with and without the Hubbard U correction, and the modified Becke–Johnson (mBJ) exchange potential. Our results indicate that the antiferromagnetic ground state is dominant in both compounds, with stronger coupling in NiSb2O6. The mBJ exchange potential provides spin magnetic moments closer to experimental values and direct band gaps of 1.80 eV and 3.88 eV for NiSb2O6 and NiTa2O6, respectively. Optical spectra indicate absorption onsets consistent with experimental observations, with NiSb2O6 exhibiting an effective optical gap of ∼2.7 eV. Band edge alignment analysis highlights the promising photocatalytic potential of NiTa2O6 for overall water splitting, aided by favorable band positions, making it particularly suitable for UV-driven photocatalysis.
{"title":"Magnetic, electronic, linear optical, and photocatalytic properties of the trirutiles NiSb2O6 and NiTa2O6 compounds","authors":"F.J.A. Santos , J.S. Jesus , R. Tartaglia , A.F. Lima","doi":"10.1016/j.physb.2026.418323","DOIUrl":"10.1016/j.physb.2026.418323","url":null,"abstract":"<div><div>In this work, we employed spin-polarized density functional theory calculations to investigate the magnetic ordering, electronic structure, linear optical response, and photocatalytic activity of NiSb<sub>2</sub>O<sub>6</sub> and NiTa<sub>2</sub>O<sub>6</sub> in the trirutile crystal structure. The calculations were carried out using the GGA-PBEsol functional, with and without the Hubbard U correction, and the modified Becke–Johnson (mBJ) exchange potential. Our results indicate that the antiferromagnetic ground state is dominant in both compounds, with stronger coupling in NiSb<sub>2</sub>O<sub>6</sub>. The mBJ exchange potential provides spin magnetic moments closer to experimental values and direct band gaps of 1.80 eV and 3.88 eV for NiSb<sub>2</sub>O<sub>6</sub> and NiTa<sub>2</sub>O<sub>6</sub>, respectively. Optical spectra indicate absorption onsets consistent with experimental observations, with NiSb<sub>2</sub>O<sub>6</sub> exhibiting an effective optical gap of ∼2.7 eV. Band edge alignment analysis highlights the promising photocatalytic potential of NiTa<sub>2</sub>O<sub>6</sub> for overall water splitting, aided by favorable band positions, making it particularly suitable for UV-driven photocatalysis.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418323"},"PeriodicalIF":2.8,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-27DOI: 10.1016/j.physb.2026.418324
I.D. Laktaev , S.G. Dorofeev , A.M. Smirnov
We report the first experimental investigation of nonlinear optical absorption in colloidal solutions of copper-doped CdSe nanotetrapods under two-photon excitation using femtosecond laser pulses. The nonlinear transmittance measurements reveal the simultaneous action of two-photon absorption and self-defocusing, resulting in pronounced asymmetry in open-aperture Z-scan profiles. The two-photon absorption coefficient was determined to be β = 0.14–0.20 cm/GW and the nonlinear refractive index ranged from – 4.9 × 10−16 to – 5.3 × 10−15 cm2/W, depending on the excitation intensity and nanostructure concentration. Additionally, we observed spatial self-phase modulation, manifested by the appearance of well-defined diffraction rings and a sharp decrease in transmittance at high laser pulse intensities. These findings demonstrate strong nonlinear optical responses in Cu-doped CdSe nanotetrapods and highlight their potential for high-sensitivity biosensing and advanced photonic applications.
{"title":"Simultaneous two-photon absorption and self-defocusing in colloidal Cu-doped CdSe nanotetrapods","authors":"I.D. Laktaev , S.G. Dorofeev , A.M. Smirnov","doi":"10.1016/j.physb.2026.418324","DOIUrl":"10.1016/j.physb.2026.418324","url":null,"abstract":"<div><div>We report the first experimental investigation of nonlinear optical absorption in colloidal solutions of copper-doped CdSe nanotetrapods under two-photon excitation using femtosecond laser pulses. The nonlinear transmittance measurements reveal the simultaneous action of two-photon absorption and self-defocusing, resulting in pronounced asymmetry in open-aperture Z-scan profiles. The two-photon absorption coefficient was determined to be β = 0.14–0.20 cm/GW and the nonlinear refractive index ranged from – 4.9 × 10<sup>−16</sup> to – 5.3 × 10<sup>−15</sup> cm<sup>2</sup>/W, depending on the excitation intensity and nanostructure concentration. Additionally, we observed spatial self-phase modulation, manifested by the appearance of well-defined diffraction rings and a sharp decrease in transmittance at high laser pulse intensities. These findings demonstrate strong nonlinear optical responses in Cu-doped CdSe nanotetrapods and highlight their potential for high-sensitivity biosensing and advanced photonic applications.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418324"},"PeriodicalIF":2.8,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-27DOI: 10.1016/j.physb.2026.418322
Grigorii V. Nenashev , Igor A. Vrublevsky , Andrey A. Ryabko , Andrey N. Aleshin , Vyacheslav A. Moshnikov
This study investigates the structural, electrical properties, and impedance characteristics of thin graphite-like carbon films deposited by electron-beam evaporation and annealed in vacuum. Raman spectroscopy reveals that the films consist mainly of sp2-hybridized carbon with graphite-like clusters of approximately 9.5 nm. Current–voltage measurements indicate space-charge-limited conduction and trap states. Impedance spectroscopy shows two overlapping relaxation processes, modeled with an equivalent circuit of two parallel branches with resistive and constant phase elements. The calculated effective capacitances were , with corresponding relaxation times of approximately respectively. The observed low-frequency nonlinear dielectric response exhibits strong dependence on the applied DC bias, leading to a pronounced decrease in the real part and increase in the imaginary part of the dielectric permittivity. This bias-controlled behavior suggests great potential for implementation in tunable capacitors and frequency-dependent energy storage components. The obtained results demonstrate the interplay between conduction and polarization processes in nanostructured carbon films and validate the relevance of the cluster-based structural model.
{"title":"Electrical conductivity and nonlinear dielectric properties of graphite-like carbon films at low frequencies","authors":"Grigorii V. Nenashev , Igor A. Vrublevsky , Andrey A. Ryabko , Andrey N. Aleshin , Vyacheslav A. Moshnikov","doi":"10.1016/j.physb.2026.418322","DOIUrl":"10.1016/j.physb.2026.418322","url":null,"abstract":"<div><div>This study investigates the structural, electrical properties, and impedance characteristics of thin graphite-like carbon films deposited by electron-beam evaporation and annealed in vacuum. Raman spectroscopy reveals that the films consist mainly of sp<sup>2</sup>-hybridized carbon with graphite-like clusters of approximately 9.5 nm. Current–voltage measurements indicate space-charge-limited conduction and trap states. Impedance spectroscopy shows two overlapping relaxation processes, modeled with an equivalent circuit of two parallel branches with resistive and constant phase elements. The calculated effective capacitances were <span><math><mrow><msub><mi>C</mi><mrow><mi>e</mi><mi>f</mi><mi>f</mi><mn>1</mn></mrow></msub><mo>=</mo><mn>4.09</mn><mo>∗</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>9</mn></mrow></msup><mspace></mspace><mi>F</mi><mspace></mspace><mtext>and</mtext></mrow></math></span> <span><math><mrow><msub><mi>C</mi><mrow><mi>e</mi><mi>f</mi><mi>f</mi><mn>2</mn></mrow></msub><mo>=</mo><mn>7.87</mn><mo>∗</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>8</mn></mrow></msup><mspace></mspace><mi>F</mi></mrow></math></span>, with corresponding relaxation times of approximately <span><math><mrow><msub><mi>τ</mi><mrow><mi>e</mi><mi>f</mi><mi>f</mi><mn>1</mn></mrow></msub><mo>=</mo><mn>1.12</mn><mo>∗</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup><mspace></mspace><mi>s</mi><mspace></mspace><mtext>and</mtext><mspace></mspace><msub><mi>τ</mi><mrow><mi>e</mi><mi>f</mi><mi>f</mi><mn>2</mn></mrow></msub><mo>=</mo><mn>3.6</mn><mo>∗</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup><mspace></mspace><mi>s</mi></mrow></math></span> respectively. The observed low-frequency nonlinear dielectric response exhibits strong dependence on the applied DC bias, leading to a pronounced decrease in the real part and increase in the imaginary part of the dielectric permittivity. This bias-controlled behavior suggests great potential for implementation in tunable capacitors and frequency-dependent energy storage components. The obtained results demonstrate the interplay between conduction and polarization processes in nanostructured carbon films and validate the relevance of the cluster-based structural model.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418322"},"PeriodicalIF":2.8,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-27DOI: 10.1016/j.physb.2026.418288
Fang-guang Kuang , Ji-chun Lian , Xiao-zhen Yan , Chuan-zhao Zhang , Jia-xin Dong , Wen-ming kang , Shu-ying Kang
Through an integrated computational approach combining first-principles calculations and crystal structure prediction, we conduct a comprehensive investigation of superconducting mechanisms in YBH8 across its potential high-pressure polymorphs. Our study elucidates the intricate relationship between crystal symmetry, electronic structure, and electron-phonon coupling (EPC) in determining superconductive properties. The C2/c phase is the most stable above 160 GPa, while the I4/mmm and Fm—3m phases exhibit strong electron-phonon coupling and high densities of states at the Fermi level, leading to predicted superconducting critical temperatures (Tc) of 144–165 K. Our analysis highlights the critical role of crystal symmetry and BHn unit configuration in achieving high-Tc superconductivity. These results establish I4/mmm and Fm—3m-YBH8 as promising superconducting candidates and provide a rational framework for extending such principles to other rare-earth borohydrides.
{"title":"Prediction of metastable YBH8 phases with high-Tc superconductivity: A first principle investigation","authors":"Fang-guang Kuang , Ji-chun Lian , Xiao-zhen Yan , Chuan-zhao Zhang , Jia-xin Dong , Wen-ming kang , Shu-ying Kang","doi":"10.1016/j.physb.2026.418288","DOIUrl":"10.1016/j.physb.2026.418288","url":null,"abstract":"<div><div>Through an integrated computational approach combining first-principles calculations and crystal structure prediction, we conduct a comprehensive investigation of superconducting mechanisms in YBH<sub>8</sub> across its potential high-pressure polymorphs. Our study elucidates the intricate relationship between crystal symmetry, electronic structure, and electron-phonon coupling (EPC) in determining superconductive properties. The <em>C</em>2/<em>c</em> phase is the most stable above 160 GPa, while the <em>I</em>4/<em>mmm</em> and <em>Fm</em>—3<em>m</em> phases exhibit strong electron-phonon coupling and high densities of states at the Fermi level, leading to predicted superconducting critical temperatures (<em>T</em><sub><em>c</em></sub>) of 144–165 K. Our analysis highlights the critical role of crystal symmetry and BH<sub>n</sub> unit configuration in achieving high-<em>T</em><sub><em>c</em></sub> superconductivity. These results establish <em>I</em>4/<em>mmm</em> and <em>Fm</em>—3<em>m-</em>YBH<sub>8</sub> as promising superconducting candidates and provide a rational framework for extending such principles to other rare-earth borohydrides.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418288"},"PeriodicalIF":2.8,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-27DOI: 10.1016/j.physb.2026.418318
A. Sánchez-Arellano , D. Ariza-Flores , J.S. Pérez-Huerta , S. Amador-Alvarado , I.A. Sustaita-Torres , J. Madrigal-Melchor
One-dimensional graphene-based photonic crystals have been identified as a promising solution for active terahertz wave tuning. However, conventional designs are constrained by the limitations of strict periodicity and uniform chemical potential distribution. The present study proposes a novel multi-periodic structure that introduces controlled variations in both the graphene chemical potential and the number of graphene layers within the unit cell. This intracell modulation, characterized by non-uniform doping, gives rise to the significant physical phenomenon of photonic band splitting. The numerical analysis was performed using the Transfer Matrix Method. Results demonstrate that the band structure splits, modifying both the number and the widths of the photonic band gaps compared to the corresponding uniform photonic crystal. Band splitting is directly correlated with the internal variations in the unit cell, enabling precise spectral engineering. These findings provide a robust framework for designing next-generation tunable multi-channel filters, optical switches, and highly tunable sensing devices.
{"title":"Splitting of the photonic bands in one-dimensional bi- and multi-periodic dielectric-graphene based photonic crystals","authors":"A. Sánchez-Arellano , D. Ariza-Flores , J.S. Pérez-Huerta , S. Amador-Alvarado , I.A. Sustaita-Torres , J. Madrigal-Melchor","doi":"10.1016/j.physb.2026.418318","DOIUrl":"10.1016/j.physb.2026.418318","url":null,"abstract":"<div><div>One-dimensional graphene-based photonic crystals have been identified as a promising solution for active terahertz wave tuning. However, conventional designs are constrained by the limitations of strict periodicity and uniform chemical potential distribution. The present study proposes a novel <em>multi-periodic</em> structure that introduces controlled variations in both the graphene chemical potential and the number of graphene layers within the unit cell. This intracell modulation, characterized by non-uniform doping, gives rise to the significant physical phenomenon of photonic band splitting. The numerical analysis was performed using the Transfer Matrix Method. Results demonstrate that the band structure splits, modifying both the number and the widths of the photonic band gaps compared to the corresponding uniform photonic crystal. Band splitting is directly correlated with the internal variations in the unit cell, enabling precise spectral engineering. These findings provide a robust framework for designing next-generation tunable multi-channel filters, optical switches, and highly tunable sensing devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418318"},"PeriodicalIF":2.8,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-23DOI: 10.1016/j.physb.2026.418313
Sami A. Al-Hussain , Magdy A. Ibrahim , Arafat Toghan , Al-Shimaa Badran , N. Roushdy , Ayman M. Mostafa , Emad M. Masoud , A.A.M. Farag
This study presents a comprehensive evaluation of the novel pyranoquinoline derivative BEHPQ as an active material for optoelectronic devices through structural, morphological, thermal, optical, and electrical analyses. Scanning electron microscopy revealed a hierarchically organized surface with 2–5 μm aggregates and nanoscale roughness (10–12 nm), features that enhance light scattering and charge transport. Thermogravimetric analysis confirmed thermal stability up to 260 °C, supporting its suitability for solution-based processing. Optical measurements revealed a direct bandgap of 2.69 eV, strong UV–visible absorption (323–518 nm), and dual photoluminescence emissions associated with π–π∗ transitions and intramolecular charge transfer. Au/BEHPQ/n-Si heterojunction devices fabricated under ambient conditions exhibited strong optoelectronic performance, including a responsivity of 2.4 × 1010 A/W, detectivity of 3.0 × 1010 Jones, and open-circuit voltage of 0.45 V under 80 mW/cm2 illumination, with favorable resistance values. These results underscore BEHPQ's promise as a versatile, solution-processable semiconductor for efficient visible-light photodetectors and hybrid photovoltaic systems.
{"title":"Fabrication and exploration of illumination intensity effects on the optoelectronic and solar cell properties of a novel benzothiazole based pyrano[3,2-c]quinoline (BEHPQ): Experimental and DFT approaches","authors":"Sami A. Al-Hussain , Magdy A. Ibrahim , Arafat Toghan , Al-Shimaa Badran , N. Roushdy , Ayman M. Mostafa , Emad M. Masoud , A.A.M. Farag","doi":"10.1016/j.physb.2026.418313","DOIUrl":"10.1016/j.physb.2026.418313","url":null,"abstract":"<div><div>This study presents a comprehensive evaluation of the novel pyranoquinoline derivative <strong>BEHPQ</strong> as an active material for optoelectronic devices through structural, morphological, thermal, optical, and electrical analyses. Scanning electron microscopy revealed a hierarchically organized surface with 2–5 μm aggregates and nanoscale roughness (10–12 nm), features that enhance light scattering and charge transport. Thermogravimetric analysis confirmed thermal stability up to 260 °C, supporting its suitability for solution-based processing. Optical measurements revealed a direct bandgap of 2.69 eV, strong UV–visible absorption (323–518 nm), and dual photoluminescence emissions associated with π–π∗ transitions and intramolecular charge transfer. Au/<strong>BEHPQ</strong>/n-Si heterojunction devices fabricated under ambient conditions exhibited strong optoelectronic performance, including a responsivity of 2.4 × 10<sup>10</sup> A/W, detectivity of 3.0 × 10<sup>10</sup> Jones, and open-circuit voltage of 0.45 V under 80 mW/cm<sup>2</sup> illumination, with favorable resistance values. These results underscore <strong>BEHPQ</strong>'s promise as a versatile, solution-processable semiconductor for efficient visible-light photodetectors and hybrid photovoltaic systems.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418313"},"PeriodicalIF":2.8,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-01-23DOI: 10.1016/j.physb.2026.418311
J. Kaštil , L.V.B. Diop , P. Král , J. Valenta , M. Míšek , Z. Arnold , O. Isnard
The influence of chemical substitution on the structural, magnetic, and electronic transport properties has been systematically investigated along the Ce2Ni2-xCuxSn series of compounds, which belong to the Kondo lattice system. Then, hydrogen insertion has been carried out to study the effect of negative pressure on their properties. Substitution of Cu for Ni leads to a linear increase of the lattice parameters, with the largest change being observed for x = 0.3, with an expansion of 0.55 % along the c-axis. The antiferromagnetic ground state of the parent compound, Ce2Ni2Sn, is progressively suppressed with increasing Cu content. A reduction in the Kondo temperature is observed upon Cu substitution for Ni, an evolution discussed in reference to the Compressible Kondo Lattice model. Hydrogen is readily absorbed by these compounds, forming hydrides that are stable in air. The highest hydrogen uptake, reaching 5.7 H atoms per formula unit, was observed for x = 0.1. In contrast, deuterium absorption is significantly lower and occurs only at elevated temperatures; nevertheless, the resulting deuterides exhibit similar unit cell expansion and magnetic behavior. Upon hydrogenation, the Sommerfeld coefficient decreases from 328 mJ mol−1 K−2 in Ce2Ni2Sn to 88 mJ mol−1 K−2 for Ce2Ni2SnDy. Hydrogen insertion is found to suppress the antiferromagnetic order in Ce2Ni2Sn, indicating the hydrogen-induced evolution of competition between RKKY magnetic exchange interaction and Kondo screening. In an attempt to prepare indium for tin-substituted variants for x ranging from 0.1 to 0.3, only the Ce2Ni2Sn0.9In0.1 alloy was found to be stable, with In substitution inducing a structural transformation from orthorhombic W2CoB2-type structure (space group Immm) to the P4/mbm symmetry. This compound exhibits a magnetically ordered state below T = 9 K, suggesting antiferromagnetic order and a second magnetic transition at 6.1 K.
{"title":"Structural, magnetic, and transport properties of Cu- and In-substituted Ce2Ni2Sn compounds and their hydrides","authors":"J. Kaštil , L.V.B. Diop , P. Král , J. Valenta , M. Míšek , Z. Arnold , O. Isnard","doi":"10.1016/j.physb.2026.418311","DOIUrl":"10.1016/j.physb.2026.418311","url":null,"abstract":"<div><div>The influence of chemical substitution on the structural, magnetic, and electronic transport properties has been systematically investigated along the Ce<sub>2</sub>Ni<sub>2-x</sub>Cu<sub>x</sub>Sn series of compounds, which belong to the Kondo lattice system. Then, hydrogen insertion has been carried out to study the effect of negative pressure on their properties. Substitution of Cu for Ni leads to a linear increase of the lattice parameters, with the largest change being observed for x = 0.3, with an expansion of 0.55 % along the c-axis. The antiferromagnetic ground state of the parent compound, Ce<sub>2</sub>Ni<sub>2</sub>Sn, is progressively suppressed with increasing Cu content. A reduction in the Kondo temperature is observed upon Cu substitution for Ni, an evolution discussed in reference to the Compressible Kondo Lattice model. Hydrogen is readily absorbed by these compounds, forming hydrides that are stable in air. The highest hydrogen uptake, reaching 5.7 H atoms per formula unit, was observed for x = 0.1. In contrast, deuterium absorption is significantly lower and occurs only at elevated temperatures; nevertheless, the resulting deuterides exhibit similar unit cell expansion and magnetic behavior. Upon hydrogenation, the Sommerfeld coefficient decreases from 328 mJ mol<sup>−1</sup> K<sup>−2</sup> in Ce<sub>2</sub>Ni<sub>2</sub>Sn to 88 mJ mol<sup>−1</sup> K<sup>−2</sup> for Ce<sub>2</sub>Ni<sub>2</sub>SnD<sub>y</sub>. Hydrogen insertion is found to suppress the antiferromagnetic order in Ce<sub>2</sub>Ni<sub>2</sub>Sn, indicating the hydrogen-induced evolution of competition between RKKY magnetic exchange interaction and Kondo screening. In an attempt to prepare indium for tin-substituted variants for x ranging from 0.1 to 0.3, only the Ce<sub>2</sub>Ni<sub>2</sub>Sn<sub>0.9</sub>In<sub>0.1</sub> alloy was found to be stable, with In substitution inducing a structural transformation from orthorhombic W<sub>2</sub>CoB<sub>2</sub>-type structure (space group Immm) to the P4/mbm symmetry. This compound exhibits a magnetically ordered state below T = 9 K, suggesting antiferromagnetic order and a second magnetic transition at 6.1 K.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418311"},"PeriodicalIF":2.8,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
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