Physica B-condensed Matter最新文献

{"title":"Microstructural, optical, and impedance studies of porous Mn-α-Fe2O3/CuO/Ag heterostructures grown using solution-based methods","authors":"Pannan I. Kyesmen ,&nbsp;Nteseng D.M. Mosalakgotla ,&nbsp;Adedapo O. Adeola ,&nbsp;Peverga R. Jubu ,&nbsp;Philip Omolaye ,&nbsp;I. Ahemen ,&nbsp;Mmantsae Diale","doi":"10.1016/j.physb.2024.416784","DOIUrl":"10.1016/j.physb.2024.416784","url":null,"abstract":"<div><div>Here, thin films of porous Mn-α-Fe₂O₃/CuO/Ag were prepared; engaging solely low-cost solution-based methods. The dip-coating of CuO on electrodeposited Mn-α-Fe₂O₃ samples using a 180-day-old Cu-based precursor produced films with inhomogeneous morphology and shallow surface pores. This morphology provided the platform for the drop-casting of Ag nanoparticles on the film's surface to form porous Mn-α-Fe₂O₃/CuO/Ag heterostructures. EDS, XRD, and Raman spectroscopy studies affirmed the film's structural integrity. The bandgap estimated for the Mn-α-Fe₂O₃/CuO/Ag samples was 3.8 % less than the values deduced for Mn-α-Fe₂O₃ films. Mott-Schottky analysis disclosed n-type semiconducting behaviour for the Mn-α-Fe₂O₃ films, which was retained after forming heterostructures with CuO and CuO/Ag. The charge transfer resistance at Mn-α-Fe₂O₃/CuO/Ag film's surface in an electrochemical system was 27 times lower than the approximate values obtained for Mn-α-Fe₂O₃ samples. This research introduces a facile and low-cost approach for fabricating porous Mn-α-Fe₂O₃/CuO/Ag heterostructures with improved properties for photo-base and optoelectronic applications.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"699 ","pages":"Article 416784"},"PeriodicalIF":2.8,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758951","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}

{"title":"Effects of film thickness on the superconductivity of LaSi2(00l)/Si(100) films","authors":"Jia Han ,&nbsp;Chuanyi Wu ,&nbsp;Yangzhou Wang ,&nbsp;Jin Wang ,&nbsp;Baojuan Kang ,&nbsp;Shixun Cao ,&nbsp;Jincang Zhang ,&nbsp;Fei Chen","doi":"10.1016/j.physb.2024.416785","DOIUrl":"10.1016/j.physb.2024.416785","url":null,"abstract":"<div><div>In this paper, we studied the superconducting properties of the LaSi₂(00<em>l</em>)/Si(100) single-crystalline thin films prepared by the molecular beam epitaxy (MBE) method with different thicknesses via electro-transport and magnetic properties measurements. The S50 (sample with deposition thickness around 50 nm) exhibits the highest superconducting transition temperature (<em>T</em>_c) of 2.62 K, which is higher than that of the bulk LaSi₂. The variation of <em>T</em>_c with film thickness is within 8 %. In addition, the upper critical field (<em>H</em>_c2) increases with reducing film thickness. Especially for the thinnest LaSi₂ film with deposition thickness around 10 nm, the <em>H</em>_c2 shows a sharp increase and the flux jump activity disappears, which is due to the defects and disorders from the interfacial effect. Our work completes the superconducting properties of LaSi₂ films, which helps to understand the influence and modulation of film thickness on superconductivity in LaSi₂ system.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"699 ","pages":"Article 416785"},"PeriodicalIF":2.8,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758952","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}

{"title":"Heusler-based topological quantum catalyst Fe2VAl with obstructed surface states for the hydrogen-evolution reaction","authors":"Yang Li","doi":"10.1016/j.physb.2024.416773","DOIUrl":"10.1016/j.physb.2024.416773","url":null,"abstract":"<div><div>Topological materials are widely esteemed for their surface metallic states and remarkable carrier mobility, making them effective catalysts for heterogeneous processes. This study showcases the outstanding properties of Fe₂VAl, an experimentally prepared compound that enjoys a Cu₂MnAl-type Heusler structure. It specifically highlights the presence of robust obstructed surface states on the (001) surface and the outstanding catalytic effectiveness of the compound in electrochemical hydrogen evolution processes (HER). The band structure calculation in this work shows that it is an obstructed atomic semimetal with a pseudo-gap of −0.088 eV (nearly −0.1 eV). These findings align with the previous optical conductivity measurements conducted at low temperatures, which also showed a similar pseudo-gap. This work suggests that the easily prepared Fe₂VAl compound may be an excellent topological quantum material for topological catalysis.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"699 ","pages":"Article 416773"},"PeriodicalIF":2.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758953","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}

{"title":"Synthetically modified mixed phase inverse spinel CuFe2O4 magnetic nanoparticles: Structure, physical, and electrochemical properties for photocatalytic applications","authors":"Devanshi Zala ,&nbsp;Abhijit Ray","doi":"10.1016/j.physb.2024.416770","DOIUrl":"10.1016/j.physb.2024.416770","url":null,"abstract":"<div><div>Copper ferrite nanoparticles with crystallite sizes between 21.8 and 27.0 nm are developed by modified co-precipitation (C), two-step hydrothermal (H), and polymer-assisted sol-gel (S) methods. The synthetic conditions caused a structure and morphology variation, resulting in their optoelectrical and electrochemical properties becoming markedly different for specific photocatalytic applications. The nanoparticles are p-type semiconducting with direct optical band-gaps between 2.06 and 2.65 eV and carrier concentrations between 10¹⁷ ∼10¹⁸ cm⁻³. Magnetization studies demonstrate that the C-sample exhibits saturation magnetization of 32.44 emu/g nearly double as compared to that of H-sample (16.4 emu/g); however, the latter shows the highest coercivity. Impedance spectroscopy reveals faster electron transfer kinetics across the grain boundaries in the S-sample. The pellets prepared from C- and S- samples have larger dielectric constants and better oxygen ion-led conductivity owing to their larger grain size. Density Functional Theory-based calculation shows that oxygen ion conductivity plays a vital role in hole transport and thus an enhancement in the photocatalytic properties. Photocatalytic activity in the H-sample is superior with a degree of methylene blue dye degradation of 55 % in 2 h and a faster rate kinetics of 0.004 min⁻¹ in the first hour under simulated sunlight.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"699 ","pages":"Article 416770"},"PeriodicalIF":2.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747954","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}

{"title":"Ternary one-dimensional photonic crystal biosensors for efficient bacteria detection: Role of quantum dots and material combinations","authors":"Fereshteh Firouzi ,&nbsp;Ali Vahedi ,&nbsp;Siamak Hagipour","doi":"10.1016/j.physb.2024.416766","DOIUrl":"10.1016/j.physb.2024.416766","url":null,"abstract":"<div><div>A ternary one-dimensional photonic crystal biosensor was proposed for quick and easy bacterial detection. The Air/(AMB)^N/D/(AMB)^N/Glass structure is formed by a defect layer between two identical periodic structures filled with samples of normal blood and bacteria-infected blood. Three categories of inorganic, organic, and inorganic/organic hybrid materials were used to make the four combinations of proposed photonic crystal biosensors. Aluminum Gallium Nitride (Al_xGa_1-xN) quantum dots, Gallium Arsenide (GaAs), silica, and polyaniline polymer have been used in the proposed structures to observe and compare their effects are in the infrared and visible regions. The results indicate that incorporating Al_xGa_1-xN and GaAs quantum dot layers has increased the sensitivity. These designs have two photonic band gaps with multiple suitable detection modes in infrared and visible regions with an approximately linear behavior. A standard blood sample (TBN) and bacterial samples (TB1 to TB7) were distinguished using the optimal parameters.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"698 ","pages":"Article 416766"},"PeriodicalIF":2.8,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745359","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}

{"title":"Polarization-independent ultranarrow ultraviolet graphene perfect absorption for temperature controlled high-performance optical switch","authors":"Lili Yu ,&nbsp;Chaojun Tang","doi":"10.1016/j.physb.2024.416767","DOIUrl":"10.1016/j.physb.2024.416767","url":null,"abstract":"<div><div>We demonstrate a tunable polarization-independent ultranarrow perfect absorption (PA) in a hybrid metasurface consisting of graphene-dielectric nanodisk-metal mirror in the ultraviolet (UV) range. Through near-field interactions between the optical dissipation of graphene and surface plasmon polaritons supported by Al₂O₃ nanodisk array on UV mirror, the UV Fano-like absorption peak can reach 99.92 % with linewidth as low as 3.4 nm, which is predicted by the impedance matching theory and a Fano model. Furthermore, a dynamic tuning of the UV PA and the associated high-performance optical switch are achieved via temperature change of the encapsulated ethanol. Importantly, the modulation depth of almost 100 %, the ultralarge modulation intensity of about 2.5 × 10⁶ and the on/off ratio of 63 dB are reached for the graphene-based switch by a thermal control. Our work holds potential applications on the UV graphene based light modulators such as high-precision optical switch and nanodevices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"698 ","pages":"Article 416767"},"PeriodicalIF":2.8,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723753","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}

{"title":"Effects of Ta on the Structural, mechanical and electronic properties of the ternary alloys TaxHf1−xN: A computational study","authors":"Riadh Guendouz ,&nbsp;Mohamed Benhamida ,&nbsp;Kamel Zanat ,&nbsp;Levente Vitos","doi":"10.1016/j.physb.2024.416749","DOIUrl":"10.1016/j.physb.2024.416749","url":null,"abstract":"<div><div>The structural, elastic and electronic properties of the ternary transition metal nitrides alloys Ta<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>Hf<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>N at (<span><math><mrow><mn>0</mn><mo>&lt;</mo><mi>x</mi><mo>&lt;</mo><mn>1</mn></mrow></math></span>) in the rock-salt structure are investigated by ab initio calculations. The calculations were performed using the first-principles Exact Muffin-Tin Orbitals method using full charge density technique within the framework of density functional theory. The compositional disorder is treated within the coherent potential approximation. The estimated formation enthalpy indicates that Ta_0.5Hf_0.5N is thermodynamically the most stable alloy. The obtained lattice parameters of the Ta<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>Hf<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>N alloys are in good agreement with other available theoretical and experimental values. The predicted elastic stiffness constants <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>11</mn></mrow></msub></math></span>, <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>12</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>44</mn></mrow></msub></math></span> indicate that the Ta<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>Hf<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>N alloys are mechanically stable and the addition of Ta increases their ductility. The Ta_0.7Hf_0.3N found to be hardest alloy. The correlation between Pettifor’s criterion (<span><math><mrow><msub><mrow><mi>C</mi></mrow><mrow><mn>12</mn></mrow></msub><mo>−</mo><msub><mrow><mi>C</mi></mrow><mrow><mn>44</mn></mrow></msub></mrow></math></span>) normalized by bulk modulus <span><math><mi>B</mi></math></span> and Pugh’s ratio <span><math><mrow><mi>G</mi><mo>/</mo><mi>B</mi></mrow></math></span> with increasing the degree of alloying x allowed us to predict that the critical value <span><math><mrow><mrow><mo>(</mo><mi>G</mi><mo>/</mo><mi>B</mi><mo>)</mo></mrow><mo>=</mo><mn>0</mn><mo>.</mo><mn>53</mn></mrow></math></span>, which correspond to x around <span><math><mrow><mn>0</mn><mo>.</mo><mn>6</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>05</mn></mrow></math></span>, marks the brittle to ductile transition.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"698 ","pages":"Article 416749"},"PeriodicalIF":2.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723801","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}

{"title":"Graphene oxide from biomass waste: A pathway to electrochemical hydrogen production and capacitive applications","authors":"Aayush Gupta ,&nbsp;Amit Kumar ,&nbsp;Sachin Jaidka ,&nbsp;Kaveri Ajravat ,&nbsp;Loveleen Kaur Brar","doi":"10.1016/j.physb.2024.416765","DOIUrl":"10.1016/j.physb.2024.416765","url":null,"abstract":"<div><div>In the pursuit of sustainable energy, hydrogen stands out as a promising alternative to fossil fuels due to its clean and efficient energy properties. This study investigates a novel approach to synthesize graphene oxide (GO) from biomass waste for sustainable hydrogen production. Three biomass sources - walnut shells, peanut shells, and parthenium hysterophorus - were used to produce GO, which was then used as electrode material in electrochemical hydrogen evolution reactions (HER). The highest yield of GO was obtained for the walnut shells (20 %). It demonstrated the best electrocatalytic performance, achieving a current density of −29.32 mA/cm² at −0.82 V, surpassing GO obtained from peanut shells and parthenium hysterophorus. A detailed structural and electrochemical analysis revealed a low Tafel slope (163.06 mV/decade), a high electrochemical surface area (25.0), and an onset potential of −0.68 V for walnut shell-derived GO. This novel use of biomass offers a renewable and affordable resource.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"698 ","pages":"Article 416765"},"PeriodicalIF":2.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723754","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}

{"title":"Organic electride C6O6Li6: A potential support for transition metal-doped single atom catalysis toward hydrogen evolution reaction (HER)","authors":"Abdulrahman Allangawi ,&nbsp;Mahdiya Salman ,&nbsp;Khurshid Ayub ,&nbsp;Mazhar Amjad Gilani ,&nbsp;Muhammad Imran ,&nbsp;Tariq Mahmood","doi":"10.1016/j.physb.2024.416762","DOIUrl":"10.1016/j.physb.2024.416762","url":null,"abstract":"<div><div>In pursuit of efficient hydrogen evolution reaction (HER) catalysts, the use of single-atom catalysts (SACs) is crucial for the full realization of hydrogen energy. This study investigates the potential of the late first row transition metals (Fe – Zn) doped C₆O₆Li₆ organic electride as a support material towards HER. The intrinsic properties such as the geometry, stability, electronic properties, and HER catalytic activity of these SACs are assessed by employing the ωB97XD functional of the density functional theory (DFT) coupled with the def2TZVP basis-set. The Fe, Ni, and Co doped SACs show high stability, whereas Cu and Zn exhibit lower stability. The electronic properties analysis indicates sufficient conductivity for the designed SACs, as evidenced by their low E_gap values. Among the studied systems, Fe/Side@C₆O₆Li₆ SAC shows the best catalytic activity with a ΔG_H∗ value of −0.55 eV. Despite this, all studied systems demonstrate low HER activity. However, this study highlights the potential of organic electrides in catalytic applications and sets the groundwork for further optimization.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"698 ","pages":"Article 416762"},"PeriodicalIF":2.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723799","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}

{"title":"Exploration of the normalized intradopant transition energy of GaAs quantum dot under the influence of noise","authors":"Bhaskar Bhakti,&nbsp;Manas Ghosh","doi":"10.1016/j.physb.2024.416731","DOIUrl":"10.1016/j.physb.2024.416731","url":null,"abstract":"<div><div>In this work the <em>intradopant transition energy (IDTE)</em> and the <em>normalized intradopant transition energy (NIDTE)</em> of <em>GaAs quantum dot (QD)</em> have been minutely explored. The QD contains <em>Gaussian impurity</em> as dopant. <em>Gaussian white noise</em>, applied via two different routes (additive and multiplicative), also becomes part of the QD confinement potential. Energy values are calculated using linear variational theory. The IDTE and NIDTE exhibit (depending on presence/absence of noise, mode of entrance of noise and the given physical parameter undergoing change) steady growth, steady fall, maximization, minimization and saturation. Throughout the entire study, the NIDTE plots efficiently highlight some weak features which IDTE plots fail to do and clearly announce their superiority over the IDTE plots in realizing the influences of various physical parameters. The findings of the study are expected to be quite relevant in elucidating the optical properties of low-dimensional nanostructures containing impurity and under the sway of noise.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"698 ","pages":"Article 416731"},"PeriodicalIF":2.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723805","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}