A quaternary derivative of the Pr 1-2-20 system, PrOs2Sn2Zn18, was successfully synthesized in single-crystal form and characterized by X-ray diffraction, specific-heat, electric resistivity and magnetic susceptibility measurements. Unlike the parent compound PrOs2Zn20, which undergoes a structural phase transition at = 87 K, no indication of such a transition was observed in PrOs2Sn2Zn18 down to the lowest temperature of 2 K. The magnetic susceptibility exhibits typical Van Vleck-type temperature-independent paramagnetism below approximately 10 K, suggesting a nonmagnetic crystalline electric field (CEF) ground state. The magnetic specific heat at low temperatures shows a Schottky anomaly centered around 6 K. Analysis based on a two-level model indicates that the CEF ground state is a doublet, with the first excited state being a triplet. These results suggest that the CEF ground state is a non-Kramers doublet. The nature of the non-Kramers ground state and the low-lying CEF excitations of Pr ion are discussed in detail. In addition, the structural stability of PrOs2Sn2Zn18 is examined in comparison with isostructural compounds, Os2Zn20 ( = La, Pr), highlighting the role of Sn substitution in suppressing structural phase transitions.
{"title":"Structural and magnetic properties of a new cubic Pr-based compound PrOs2Sn2Zn18","authors":"Shuto Tamura , Kazuhei Wakiya , Mitsuteru Nakamura , Takanori Taniguchi , Masahito Yoshizawa , Yoshiki Nakanishi","doi":"10.1016/j.physb.2026.418297","DOIUrl":"10.1016/j.physb.2026.418297","url":null,"abstract":"<div><div>A quaternary derivative of the Pr 1-2-20 system, PrOs<sub>2</sub>Sn<sub>2</sub>Zn<sub>18</sub>, was successfully synthesized in single-crystal form and characterized by X-ray diffraction, specific-heat, electric resistivity and magnetic susceptibility measurements. Unlike the parent compound PrOs<sub>2</sub>Zn<sub>20</sub>, which undergoes a structural phase transition at <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>S</mi></mrow></msub></math></span> = 87 K, no indication of such a transition was observed in PrOs<sub>2</sub>Sn<sub>2</sub>Zn<sub>18</sub> down to the lowest temperature of 2 K. The magnetic susceptibility <span><math><mi>χ</mi></math></span> exhibits typical Van Vleck-type temperature-independent paramagnetism below approximately 10 K, suggesting a nonmagnetic crystalline electric field (CEF) ground state. The magnetic specific heat at low temperatures shows a Schottky anomaly centered around 6 K. Analysis based on a two-level model indicates that the CEF ground state is a doublet, with the first excited state being a triplet. These results suggest that the CEF ground state is a non-Kramers <span><math><msub><mrow><mi>Γ</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> doublet. The nature of the non-Kramers ground state and the low-lying CEF excitations of Pr<span><math><msup><mrow></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></math></span> ion are discussed in detail. In addition, the structural stability of PrOs<sub>2</sub>Sn<sub>2</sub>Zn<sub>18</sub> is examined in comparison with isostructural compounds, <span><math><mi>R</mi></math></span>Os<sub>2</sub>Zn<sub>20</sub> (<span><math><mi>R</mi></math></span> = La, Pr), highlighting the role of Sn substitution in suppressing structural phase transitions.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418297"},"PeriodicalIF":2.8,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038240","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 : 2026-01-16DOI: 10.1016/j.physb.2026.418294
Sain Bux Jamali , Zain Ul Abideen , Murad Ali Khaskheli , Muhammad Ilyas Abro , Maheen Malik , Muhammad Akram , Sikandar Ali
Au@Ag nanocuboids were successfully fabricated via symmetric Ag overgrowth on Au-nanorods (NRs) nanocuboids. The seed Au/Ag and AuNRs molar ratios were found to be the same during the synthesis of different-sized core-shell nanocuboids. Adsorption measurements were used to validate the nanocuboids production. The thickness of the core-shell nanorods was systematically adjusted by changing the size of the core particles and the quantity of AgNO3. Using the same concentration of mercaptobenzoic acid (MBA) probe molecules, the core-shell nanocuboids of various sizes that were produced exhibited highly effective surface enhanced Raman spectroscopy (SERS). The nanoparticle size dependent SERS effect was confirmed by the simulation results of electromagnetic (EM) field distribution by finite difference time domain (FDTD) method. The SERS performance was significantly optimized by tuning the excitation laser wavelength from 532 to 638 nm, which allowed the 110 nm and 130 nm nanocuboids to serve as ideal substrates for SERS, thus underscoring their potential for diverse applications.
{"title":"Au@Ag nano cuboids with tunable surface plasmon resonance: A pathway to high-performance and chemically stable SERS substrates","authors":"Sain Bux Jamali , Zain Ul Abideen , Murad Ali Khaskheli , Muhammad Ilyas Abro , Maheen Malik , Muhammad Akram , Sikandar Ali","doi":"10.1016/j.physb.2026.418294","DOIUrl":"10.1016/j.physb.2026.418294","url":null,"abstract":"<div><div>Au@Ag nanocuboids were successfully fabricated <em>via</em> symmetric Ag overgrowth on Au-nanorods (NRs) nanocuboids. The seed Au/Ag and AuNRs molar ratios were found to be the same during the synthesis of different-sized core-shell nanocuboids. Adsorption measurements were used to validate the nanocuboids production. The thickness of the core-shell nanorods was systematically adjusted by changing the size of the core particles and the quantity of AgNO<sub>3</sub>. Using the same concentration of mercaptobenzoic acid (MBA) probe molecules, the core-shell nanocuboids of various sizes that were produced exhibited highly effective surface enhanced Raman spectroscopy (SERS). The nanoparticle size dependent SERS effect was confirmed by the simulation results of electromagnetic (EM) field distribution by finite difference time domain (FDTD) method. The SERS performance was significantly optimized by tuning the excitation laser wavelength from 532 to 638 nm, which allowed the 110 nm and 130 nm nanocuboids to serve as ideal substrates for SERS, thus underscoring their potential for diverse applications.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418294"},"PeriodicalIF":2.8,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038242","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}
We have investigated the electronic properties of NaGeAs in its hexagonal crystal structure using first-principles calculations. The electronic band structures were computed both without and with the inclusion of spin–orbit coupling (SOC). A detailed analysis of the SOC-induced band structure reveals a distinct spin splitting near the Fermi level, particularly evident in the valence band, which is attributed to the absence of inversion symmetry in the crystal. This splitting exhibits Rashba-like characteristics, making NaGeAs a promising candidate for spintronic applications. The tunable nature of Rashba-type spin splitting in the valence band of such non-centrosymmetric materials opens avenues for their integration into next-generation spin-based electronic devices.
{"title":"Electronic properties of NaGeAs: First principles calculations","authors":"Varun Tiwari , Shivendra Kumar Gupta , Balwant Singh Arya , Mahendra Aynyas","doi":"10.1016/j.physb.2026.418287","DOIUrl":"10.1016/j.physb.2026.418287","url":null,"abstract":"<div><div>We have investigated the electronic properties of NaGeAs in its hexagonal crystal structure using first-principles calculations. The electronic band structures were computed both without and with the inclusion of spin–orbit coupling (SOC). A detailed analysis of the SOC-induced band structure reveals a distinct spin splitting near the Fermi level, particularly evident in the valence band, which is attributed to the absence of inversion symmetry in the crystal. This splitting exhibits Rashba-like characteristics, making NaGeAs a promising candidate for spintronic applications. The tunable nature of Rashba-type spin splitting in the valence band of such non-centrosymmetric materials opens avenues for their integration into next-generation spin-based electronic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418287"},"PeriodicalIF":2.8,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081203","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}
We present a comprehensive study on the electronic, magnetic, and structural properties of the antiperovskite compound SnNCo3 to investigate its proximity to a ferromagnetic quantum critical point (FM-QCP). Motivated by experimental observations indicating strong electron correlations and spin-glass-like behavior in the absence of long-range magnetic order, we employ density functional theory (DFT) within the local spin density approximation (LSDA), complemented by LSDA+ and fixed spin moment (FSM) methodologies. Surprisingly, our calculations reveal a ferromagnetic ground state with a substantial density of states at the Fermi level, dominated by Co orbitals. The Stoner criteria suggests a magnetic instability in the system, and the ferromagnetic state is energetically favored over antiferromagnetic and nonmagnetic configurations. However, incorporating electron correlations and nitrogen vacancy disorder reveals that strong spin fluctuations significantly renormalize the magnetic energy landscape. Given the absence of long-range magnetic order in the material, we employed the Ginzburg–Landau analysis using FSM calculations, which uncovers soft longitudinal spin fluctuations exceeding the self-consistent Co moment, signaling proximity to ferromagnetic quantum criticality. These findings highlight the subtle interplay of electronic correlations, chemical bonding, and spin fluctuations in driving the magnetism in SnNCo3, and position it as a promising candidate for exploring itinerant ferromagnetic quantum critical behavior in nitride antiperovskites.
{"title":"Effects of non-stoichiometry on the incipient magnetic properties of SnNCo3","authors":"Pragya Tripathi , Himanshu , Murali Rangarajan , J.J. Pulikkotil","doi":"10.1016/j.physb.2026.418293","DOIUrl":"10.1016/j.physb.2026.418293","url":null,"abstract":"<div><div>We present a comprehensive study on the electronic, magnetic, and structural properties of the antiperovskite compound SnNCo<sub>3</sub> to investigate its proximity to a ferromagnetic quantum critical point (FM-QCP). Motivated by experimental observations indicating strong electron correlations and spin-glass-like behavior in the absence of long-range magnetic order, we employ density functional theory (DFT) within the local spin density approximation (LSDA), complemented by LSDA+<span><math><msub><mrow><mi>U</mi></mrow><mrow><mi>e</mi><mi>f</mi><mi>f</mi></mrow></msub></math></span> and fixed spin moment (FSM) methodologies. Surprisingly, our calculations reveal a ferromagnetic ground state with a substantial density of states at the Fermi level, dominated by Co <span><math><mrow><mn>3</mn><mi>d</mi></mrow></math></span> orbitals. The Stoner criteria suggests a magnetic instability in the system, and the ferromagnetic state is energetically favored over antiferromagnetic and nonmagnetic configurations. However, incorporating electron correlations and nitrogen vacancy disorder reveals that strong spin fluctuations significantly renormalize the magnetic energy landscape. Given the absence of long-range magnetic order in the material, we employed the Ginzburg–Landau analysis using FSM calculations, which uncovers soft longitudinal spin fluctuations exceeding the self-consistent Co moment, signaling proximity to ferromagnetic quantum criticality. These findings highlight the subtle interplay of electronic correlations, chemical bonding, and spin fluctuations in driving the magnetism in SnNCo<sub>3</sub>, and position it as a promising candidate for exploring itinerant ferromagnetic quantum critical behavior in nitride antiperovskites.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418293"},"PeriodicalIF":2.8,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038254","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}
<div><div>Heterogeneous photocatalysis is a semiconductor-based method that converts solar energy into clean chemical energy through water splitting, thus producing green dihydrogen (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>), which represents a promising energy carrier. Motivated by the clean nature of the produced energy, the Janus materials ZnSiSSe and ZnSiSeTe have been proposed in this work as potential candidates for water splitting. First-principles calculations based on density functional theory (DFT) were performed to evaluate their performance. The ZnSiSSe and ZnSiSeTe materials are indirect semiconductors, with band gaps calculated using the HSE06 method of 1.28 eV and 1.13 eV, respectively. The ZnSiSSe and ZnSiSeTe structures exhibit significant absorption in the visible range, with absorption coefficients reaching <span><math><mrow><mn>1</mn><mo>.</mo><mn>7</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span> cm<sup>−1</sup> for ZnSiSSe and <span><math><mrow><mn>3</mn><mo>.</mo><mn>3</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span> cm<sup>−1</sup> for ZnSiSeTe, extending into the ultraviolet region. The conduction band maximum (CBM) and valence band minimum (VBM) levels appropriately frame the water redox potentials under acidic and neutral conditions and even in a basic medium. Excellent carrier migration affinity is ensured by the effective masses and electron mobility, where the electron effective mass is approximately (<span><math><mrow><mo>≈</mo><mn>2</mn></mrow></math></span> fold) higher than that of holes in ZnSiSSe and (4.3 fold) higher in ZnSiSeTe, with mobilities reaching <span><math><mrow><mn>1</mn><mo>.</mo><mn>09</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> V<sup>−1</sup> s<sup>−1</sup> and <span><math><mrow><mn>3</mn><mo>.</mo><mn>5</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> V<sup>−1</sup> s<sup>−1</sup>, respectively, surpassing several systematically studied materials. The hydrogen conversion efficiency (STH) of ZnSiSSe (24.89%) and ZnSiSeTe (26.89%) significantly exceeds the theoretical value (18%) for <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> production, surpassing that of several materials. The structures also show excellent solar-to-hydrogen (STH) conversion efficiency under compressive strain. Under a -5% strain, the STH reaches (30.4%) for ZnSiSSe and (30.2%) for ZnSiSeTe. The free energy calculation indicates that the structures ZnSiSSe and ZnSiSeTe exhibit high performance under light irradiation for activating the hydrogen evolution reaction (
{"title":"Synergistic optimization of optical and electronic properties in Janus ZnSiSSe and ZnSiSeTe for solar-driven hydrogen evolution","authors":"Abdelmajid Es-saadi , Zakaryae Haman , Moussa Kibbou , Lahcen Aznague , El-m’feddal Adadi , Ismail Essaoudi , Abdelmajid Ainane","doi":"10.1016/j.physb.2026.418292","DOIUrl":"10.1016/j.physb.2026.418292","url":null,"abstract":"<div><div>Heterogeneous photocatalysis is a semiconductor-based method that converts solar energy into clean chemical energy through water splitting, thus producing green dihydrogen (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>), which represents a promising energy carrier. Motivated by the clean nature of the produced energy, the Janus materials ZnSiSSe and ZnSiSeTe have been proposed in this work as potential candidates for water splitting. First-principles calculations based on density functional theory (DFT) were performed to evaluate their performance. The ZnSiSSe and ZnSiSeTe materials are indirect semiconductors, with band gaps calculated using the HSE06 method of 1.28 eV and 1.13 eV, respectively. The ZnSiSSe and ZnSiSeTe structures exhibit significant absorption in the visible range, with absorption coefficients reaching <span><math><mrow><mn>1</mn><mo>.</mo><mn>7</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span> cm<sup>−1</sup> for ZnSiSSe and <span><math><mrow><mn>3</mn><mo>.</mo><mn>3</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span> cm<sup>−1</sup> for ZnSiSeTe, extending into the ultraviolet region. The conduction band maximum (CBM) and valence band minimum (VBM) levels appropriately frame the water redox potentials under acidic and neutral conditions and even in a basic medium. Excellent carrier migration affinity is ensured by the effective masses and electron mobility, where the electron effective mass is approximately (<span><math><mrow><mo>≈</mo><mn>2</mn></mrow></math></span> fold) higher than that of holes in ZnSiSSe and (4.3 fold) higher in ZnSiSeTe, with mobilities reaching <span><math><mrow><mn>1</mn><mo>.</mo><mn>09</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> V<sup>−1</sup> s<sup>−1</sup> and <span><math><mrow><mn>3</mn><mo>.</mo><mn>5</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> V<sup>−1</sup> s<sup>−1</sup>, respectively, surpassing several systematically studied materials. The hydrogen conversion efficiency (STH) of ZnSiSSe (24.89%) and ZnSiSeTe (26.89%) significantly exceeds the theoretical value (18%) for <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> production, surpassing that of several materials. The structures also show excellent solar-to-hydrogen (STH) conversion efficiency under compressive strain. Under a -5% strain, the STH reaches (30.4%) for ZnSiSSe and (30.2%) for ZnSiSeTe. The free energy calculation indicates that the structures ZnSiSSe and ZnSiSeTe exhibit high performance under light irradiation for activating the hydrogen evolution reaction (","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418292"},"PeriodicalIF":2.8,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038255","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 : 2026-01-15DOI: 10.1016/j.physb.2026.418289
Aitijhya Saha , Debraj Rakshit
In this work, we consider a non-Hermitian system described via a one-dimensional single-particle tight-binding model, where the non-Hermiticity is governed by random nearest-neighbour tunnellings, such that the left-to-right and right-to-left hopping strengths are unequal. A physical situation of a completely real eigenspectrum arises owing to the Hamiltonian’s tridiagonal matrix structure under a simple sign conservation of the product of the conjugate nearest-neighbour tunnelling terms. The off-diagonal disorder leads the non-Hermitian system to a delocalization–localization crossover in finite systems. The emergent nature of the crossover is recognized through a finite-size spectral analysis. The system enters into a localized phase for infinitesimal disorder strength in the thermodynamic limit. We perform a careful scaling analysis of localization length, inverse participation ratio (IPR), and energy splitting and report the corresponding scaling exponents. Noticeably, in contrast to the diagonal disorder, the density of states (DOS) has a singularity at in the presence of the off-diagonal disorder, and the corresponding wavefunction remains delocalized for any given disorder strength.
{"title":"Localization with non-Hermitian off-diagonal disorder","authors":"Aitijhya Saha , Debraj Rakshit","doi":"10.1016/j.physb.2026.418289","DOIUrl":"10.1016/j.physb.2026.418289","url":null,"abstract":"<div><div>In this work, we consider a non-Hermitian system described via a one-dimensional single-particle tight-binding model, where the non-Hermiticity is governed by random nearest-neighbour tunnellings, such that the left-to-right and right-to-left hopping strengths are unequal. A physical situation of a completely real eigenspectrum arises owing to the Hamiltonian’s tridiagonal matrix structure under a simple <em>sign conservation</em> of the product of the conjugate nearest-neighbour tunnelling terms. The off-diagonal disorder leads the non-Hermitian system to a delocalization–localization crossover in finite systems. The emergent nature of the crossover is recognized through a finite-size spectral analysis. The system enters into a localized phase for infinitesimal disorder strength in the thermodynamic limit. We perform a careful scaling analysis of localization length, inverse participation ratio (IPR), and energy splitting and report the corresponding scaling exponents. Noticeably, in contrast to the diagonal disorder, the density of states (DOS) has a singularity at <span><math><mrow><mi>E</mi><mo>=</mo><mn>0</mn></mrow></math></span> in the presence of the off-diagonal disorder, and the corresponding wavefunction remains delocalized for any given disorder strength.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418289"},"PeriodicalIF":2.8,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978741","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}
We report on the observation on proximity-induced superconductivity in the topological insulator BiSbTeSe2 coupled to a disordered superconductor, amorphous indium oxide (a-InO). Resistance-temperature measurements reveal superconducting signatures at low temperatures, even when InO is in an insulating state, indicating the persistence of superconducting correlations. Differential conductance measurements exhibit a prominent zero-bias conductance peak, along with multiple peaks at higher biases, suggestive of multiple Andreev reflections. Above 10 K, the zero-bias peak and conductance oscillations vanish, marking the critical temperature (T∗) of the superconducting islands in InO. These results underscore the influence of topological surface states on proximity-induced superconductivity and highlight the role of superconducting fluctuations in disordered superconductor/topological-insulator hybrid interfaces.
{"title":"Conductance oscillations in a topological insulator–disordered superconductor hybrid interface","authors":"Jagadis Prasad Nayak , Aviad Frydman , Gopi Nath Daptary","doi":"10.1016/j.physb.2026.418248","DOIUrl":"10.1016/j.physb.2026.418248","url":null,"abstract":"<div><div>We report on the observation on proximity-induced superconductivity in the topological insulator BiSbTeSe<sub>2</sub> coupled to a disordered superconductor, amorphous indium oxide (a-InO). Resistance-temperature measurements reveal superconducting signatures at low temperatures, even when InO is in an insulating state, indicating the persistence of superconducting correlations. Differential conductance measurements exhibit a prominent zero-bias conductance peak, along with multiple peaks at higher biases, suggestive of multiple Andreev reflections. Above 10 K, the zero-bias peak and conductance oscillations vanish, marking the critical temperature (T∗) of the superconducting islands in InO. These results underscore the influence of topological surface states on proximity-induced superconductivity and highlight the role of superconducting fluctuations in disordered superconductor/topological-insulator hybrid interfaces.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418248"},"PeriodicalIF":2.8,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978739","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}
Single-atom catalysts (SACs) have attracted significant attention in energy, environmental, and materials sciences due to their maximized atomic utilization and highly tunable properties Experimental characterization reveal that small atomic clusters or nanoparticles may still be present in the SACs and altering the catalytic performance, but the underlying mechanism remains elusive. Herein, based on experimentally synthesized NiN4-doped carbon nanosheets, the first-principles calculations based on density functional theory (DFT) were performed and discovered that Ni4 clusters can effectively modulate the electronic structure of Ni single atoms to significantly reduce the oxygen evolution reaction (OER) overpotential from 1.074 V for NiN4-graphene to 0.617 V for NiN4-graphene/Ni4. By varying the type of metal clusters to form NiN4-graphene/M4 heterostructures, the OER activity can be further enhanced with the NiN4-graphene/Fe4 system exhibiting the lowest OER overpotential of 0.373 V. Electronic structure analyses, including bader charge and density of states (DOS), reveal that the metal clusters elevate the d-band center of the Ni single atom to enhance the adsorption of oxygenates. Frontier orbital and crystal orbital Hamiltonian population (COHP) analyses demonstrate that the metal clusters can modify the highest occupied states of Ni single atom, thereby regulating the interaction strength between O-p and Ni-d orbitals, and ultimately optimizing the adsorption energy of intermediates with improved catalytic activity. The present findings highlight the crucial role of small metal clusters in improving the activity of SACs and elucidate the underlying mechanism, which provides a new insight into the performance optimization of SACs.
{"title":"Enhanced oxygen evolution of NiN4-graphene by small metal clusters: A DFT study","authors":"Xilin Zhang, Xinru Cheng, Qingfang Chang, Yanxing Zhang","doi":"10.1016/j.physb.2026.418273","DOIUrl":"10.1016/j.physb.2026.418273","url":null,"abstract":"<div><div>Single-atom catalysts (SACs) have attracted significant attention in energy, environmental, and materials sciences due to their maximized atomic utilization and highly tunable properties Experimental characterization reveal that small atomic clusters or nanoparticles may still be present in the SACs and altering the catalytic performance, but the underlying mechanism remains elusive. Herein, based on experimentally synthesized NiN<sub>4</sub>-doped carbon nanosheets, the first-principles calculations based on density functional theory (DFT) were performed and discovered that Ni<sub>4</sub> clusters can effectively modulate the electronic structure of Ni single atoms to significantly reduce the oxygen evolution reaction (OER) overpotential from 1.074 V for NiN<sub>4</sub>-graphene to 0.617 V for NiN<sub>4</sub>-graphene/Ni<sub>4</sub>. By varying the type of metal clusters to form NiN<sub>4</sub>-graphene/M<sub>4</sub> heterostructures, the OER activity can be further enhanced with the NiN<sub>4</sub>-graphene/Fe<sub>4</sub> system exhibiting the lowest OER overpotential of 0.373 V. Electronic structure analyses, including bader charge and density of states (DOS), reveal that the metal clusters elevate the d-band center of the Ni single atom to enhance the adsorption of oxygenates. Frontier orbital and crystal orbital Hamiltonian population (COHP) analyses demonstrate that the metal clusters can modify the highest occupied states of Ni single atom, thereby regulating the interaction strength between O-<em>p</em> and Ni-<em>d</em> orbitals, and ultimately optimizing the adsorption energy of intermediates with improved catalytic activity. The present findings highlight the crucial role of small metal clusters in improving the activity of SACs and elucidate the underlying mechanism, which provides a new insight into the performance optimization of SACs.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418273"},"PeriodicalIF":2.8,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978742","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}
The thermoelectric performance of single-layer transition manganese trifluoride MnF3 based on the Nernst effect was investigated using first-principles calculations. Analysis of the electronic structure confirmed that MnF3 is a ferromagnetic Dirac half-metal, consistent with the previous results. Based on the magnetic anisotropy energy, we also confirmed that the in-plane ferromagnetic order as the magnetic orientation. Although the anomalous Nernst coefficients were small for all configurations, thermoelectric performance in the out-of-plane ferromagnetic order was superior to the in-plane ferromagnetic order in the absence of doping. Conversely, thermoelectric performance in the in-plane ferromagnetic order was better than that in the out-of-plane ferromagnetic order by introducing doping. Some integer Chern numbers ( and ), with or without doping, were found only in the out-of-plane ferromagnetic order when the Hubbard correction was included, suggesting single-layer MnF3 as a potential candidate for thermoelectric materials.
{"title":"Nernst-effect-based thermoelectric performance in single-layer manganese trifluorides MnF3","authors":"Teguh Budi Prayitno , Esmar Budi , Riser Fahdiran , Yanoar Pribadi Sarwono","doi":"10.1016/j.physb.2026.418262","DOIUrl":"10.1016/j.physb.2026.418262","url":null,"abstract":"<div><div>The thermoelectric performance of single-layer transition manganese trifluoride MnF<sub>3</sub> based on the Nernst effect was investigated using first-principles calculations. Analysis of the electronic structure confirmed that MnF<sub>3</sub> is a ferromagnetic Dirac half-metal, consistent with the previous results. Based on the magnetic anisotropy energy, we also confirmed that the in-plane ferromagnetic order as the magnetic orientation. Although the anomalous Nernst coefficients were small for all configurations, thermoelectric performance in the out-of-plane ferromagnetic order was superior to the in-plane ferromagnetic order in the absence of doping. Conversely, thermoelectric performance in the in-plane ferromagnetic order was better than that in the out-of-plane ferromagnetic order by introducing doping. Some integer Chern numbers (<span><math><mrow><mi>C</mi><mo>=</mo><mn>1</mn></mrow></math></span> and <span><math><mrow><mi>C</mi><mo>=</mo><mo>−</mo><mn>1</mn></mrow></math></span>), with or without doping, were found only in the out-of-plane ferromagnetic order when the Hubbard correction was included, suggesting single-layer MnF<sub>3</sub> as a potential candidate for thermoelectric materials.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"726 ","pages":"Article 418262"},"PeriodicalIF":2.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978659","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 : 2026-01-12DOI: 10.1016/j.physb.2026.418272
Ruihua Ding , Ye Tao , Feng Zeng , Fujiang Chen
Recent theoretical studies have predicted that TH graphyne, a two-dimensional carbon allotrope with a unique sp–sp2 hybridized structure, exhibits exceptional mechanical properties, including high tensile strength and tunable elastic behavior. These earlier investigations primarily focused on small-scale models and idealized loading conditions, suggesting that TH graphyne could serve as a promising candidate for advanced nanomechanical applications. However, the size-dependent mechanical response and failure mechanisms under realistic structural imperfections remain largely unexplored. In this study, we perform large-scale molecular dynamics simulations using AIREBO force field to investigate the mechanical behavior of TH graphyne nanosheets with varying sizes and edge morphologies. Our results reveal a clear reduction in both stiffness and strength with increasing system size, which is attributed to stress concentration at free edges and the increased likelihood of defect-initiated fracture. These findings align with established size effects observed in graphene and highlight the importance of edge quality in determining the effective mechanical performance of TH graphyne.
{"title":"Elastic modulus, strength, and ductility of TH graphyne: A comprehensive study of layers, defects, and thermal effects","authors":"Ruihua Ding , Ye Tao , Feng Zeng , Fujiang Chen","doi":"10.1016/j.physb.2026.418272","DOIUrl":"10.1016/j.physb.2026.418272","url":null,"abstract":"<div><div>Recent theoretical studies have predicted that TH graphyne, a two-dimensional carbon allotrope with a unique sp–sp<sup>2</sup> hybridized structure, exhibits exceptional mechanical properties, including high tensile strength and tunable elastic behavior. These earlier investigations primarily focused on small-scale models and idealized loading conditions, suggesting that TH graphyne could serve as a promising candidate for advanced nanomechanical applications. However, the size-dependent mechanical response and failure mechanisms under realistic structural imperfections remain largely unexplored. In this study, we perform large-scale molecular dynamics simulations using AIREBO force field to investigate the mechanical behavior of TH graphyne nanosheets with varying sizes and edge morphologies. Our results reveal a clear reduction in both stiffness and strength with increasing system size, which is attributed to stress concentration at free edges and the increased likelihood of defect-initiated fracture. These findings align with established size effects observed in graphene and highlight the importance of edge quality in determining the effective mechanical performance of TH graphyne.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"727 ","pages":"Article 418272"},"PeriodicalIF":2.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039948","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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