Physica B-condensed Matter最新文献

{"title":"Synthesis, characterization, electrochemical impedance spectroscopy performance and photodegradation of methylene blue: Mesoporous PEG/TiO2 by sol-gel electrospinning","authors":"Dieketseng Tsotetsi ,&nbsp;Tumelo Seadira ,&nbsp;Pontsho Mbule ,&nbsp;Mokhotjwa Dhlamini","doi":"10.1016/j.physb.2024.416627","DOIUrl":"10.1016/j.physb.2024.416627","url":null,"abstract":"<div><div>Sol-gel and electrospinning methods successfully prepared porous TiO₂ fibers. The samples were calcined at temperatures of 450 °C and 550 °C and characterized using different techniques. XRD analysis also revealed crystalline anatase and rutile phases of mp-TiO₂ observed at calcining temperatures of 450 °C and 550 °C, whereas as-prepared showed an amorphous-like structure. Relatively higher surface area and photocatalytic efficiency were increased with a decrease in crystallite size. All samples absorb UV region. The Rs value of TiO₂ calcined at 550 °C was 16.6 Ω, which is much lower than those of the 450 °C calcined TiO₂ powder electrode (52.7 Ω) and as-prepared TiO₂ electrode (95.3 Ω). In addition, the Rp resistance of TiO₂ calcined at 550 °C electrode (5.85 kΩ) was also lower than those of 450 °C calcined TiO₂ powder (39.0 kΩ) and as-prepared TiO₂ electrode (68.9 kΩ), revealing better electronic and ionic conduction of TiO₂ calcined at 550 °C electrode.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416627"},"PeriodicalIF":2.8,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, morphological and optical properties of the La2W2O9/Fe2O3 composite for UV-shielding applications","authors":"J. Louafi ,&nbsp;L.H. Omari ,&nbsp;M. Ghliyem ,&nbsp;O. Bajjou ,&nbsp;Y. Lachtioui ,&nbsp;Z. Yamkane ,&nbsp;A. Elbasset","doi":"10.1016/j.physb.2024.416618","DOIUrl":"10.1016/j.physb.2024.416618","url":null,"abstract":"<div><div>Currently, research has been conducted on the individual oxides La₂W₂O₉ and Fe₂O₃ but not on its composite form. Using a solid-state reaction technique, a La₂W₂O₉/Fe₂O₃ composite was created. A particular calcination cycle was followed by mixing the raw precursors. Scanning electron microscopy (SEM) was used to investigate the morphological microstructure, and X-ray diffraction (XRD) was used to examine the structural characteristics. The thermal and gravimetric properties were examined via differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The optical characteristics were investigated via UV–visible spectroscopy, which investigated included the transmittance, absorbance, absorption coefficient, band gap (E_g), penetration depth (β), Urbach energy (E_U), refractive index, optical conductivity, and dielectric function. These findings indicate that the optical properties improved after the addition of Fe₂O₃ compared with those of pure La₂W₂O₉. The La₂W₂O₉/Fe₂O₃ composite holds promise as a prospective material for use in the fields of sunscreen products, UV shielding or solar filtration.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416618"},"PeriodicalIF":2.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442319","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":"Photoluminescence properties of SnO2 nanoparticles doped with group VI elements (Cr, Mo, W) synthesized by pulsed laser ablation in liquid","authors":"F. Mondaca ,&nbsp;M. Arias ,&nbsp;Nicolaza Pariona ,&nbsp;Martín Herrera-Trejo ,&nbsp;C.R. Garcia ,&nbsp;A.I. Mtz-Enriquez","doi":"10.1016/j.physb.2024.416625","DOIUrl":"10.1016/j.physb.2024.416625","url":null,"abstract":"<div><div>Tin oxide nanoparticles (SnO₂ NPs), both pure and doped with Group VI (G6) metal ions (Cr⁺³, Mo⁺⁵, and W⁺⁶), were synthesized using pulsed laser ablation in liquid. This study aimed to investigate the effect of G6 doping on the electronic properties of SnO₂ NPs, with an emphasis on enhancing their photoluminescence for optoelectronic applications. Transmission electron microscopy revealed well-crystallized samples with diameters of 3–6 nm, indicating quantum-confinement effects. The optical band gap, determined by UV–Vis spectroscopy, was reduced from 5.1 <em>e</em>V (undoped) to 4.9 <em>e</em>V (Cr-doped) due to defect states, while increasing to 5.3 <em>e</em>V and 5.7 <em>e</em>V for Mo- and W-doped SnO₂, respectively, due to the Moss-Burstein effect. The photoluminescence spectra exhibited a redshift, with strong red emission around 700 nm, which was up to 90 % more intense than that of the undoped SnO₂. This enhancement was attributed to the ²E→⁴A₂ transition and increased defect states.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416625"},"PeriodicalIF":2.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446536","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":"Gradient distribution of cations in rhabdophane La0.27Y0.73PO4·nH2O nanoparticles","authors":"M.O. Enikeeva ,&nbsp;O.V. Proskurina ,&nbsp;E.Yu. Gerasimov ,&nbsp;Yu.E. Gorshkova ,&nbsp;A.A. Naberezhnov ,&nbsp;V.V. Gusarov","doi":"10.1016/j.physb.2024.416623","DOIUrl":"10.1016/j.physb.2024.416623","url":null,"abstract":"<div><div>The structure of gradient rhabdophane nanoparticles of variable composition (La,Y)PO₄·<em>n</em>H₂O obtained by precipitation is considered. According to the data of HAADF TEM and EDX mapping using the Abel inversion procedure, it was shown that there is an inhomogeneous distribution of yttrium and lanthanum atoms in the particles from the central part to the periphery. At the same time, the nominal composition of both individual nanoparticles and the entire sample meets the value specified during synthesis within the error of the method – La_0.27Y_0.73PO₄·<em>n</em>H₂O. According to SAXS data, it was determined that in the particles of (La,Y)PO₄·<em>n</em>H₂O, there is a redistribution of scattering densities, which is caused by an increase in the fraction of YPO₄ in the peripheral region of the particles. The observed effect of the distribution of cations over the particle made it possible to determine the size of the gradient layer, which reaches 50 % of the total particle size.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416623"},"PeriodicalIF":2.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441703","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":"Short and long range ordering on dielectric relaxation of AgI doped glass-ceramic","authors":"Asmita Poddar ,&nbsp;Prolay Halder ,&nbsp;Madhab Roy ,&nbsp;Sanjib Bhattacharya","doi":"10.1016/j.physb.2024.416557","DOIUrl":"10.1016/j.physb.2024.416557","url":null,"abstract":"<div><div>The dielectric relaxation process of an amorphous glassy system, AgI - CdO -V₂O₅ -P₂O₅ - ZnO has been reported here. Electric modulus formalism has been carried out to explore the dielectric behavior of the as-prepared samples and the experimental results have been analyzed in the light of some theoretical models. Study of the nature of peak separation between imaginary components of electric modulus and the complex impedance plots reveals that the present system with lower AgI content should have a tendency to exhibit long range order for the relaxation of charge carriers. On the other hand, the present system with higher AgI content exhibits a relaxation process, dominated by short range order of charge carriers. This relaxation process is found to be Debye type for AgI doping up to x = 0.20 and it becomes non-Debye type beyond that composition range.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416557"},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578441","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":"Anisotropic magnetic entropy change and magnetic critical behavior in van der Waals Fe3GaTe2","authors":"Cuicui Hu ,&nbsp;Fang Tang ,&nbsp;Lina Jiang ,&nbsp;Yang Chen ,&nbsp;Haifeng Chen ,&nbsp;Zilu Xia ,&nbsp;Yong Fang ,&nbsp;Haicheng Xuan ,&nbsp;Bin Qian ,&nbsp;Zhida Han","doi":"10.1016/j.physb.2024.416615","DOIUrl":"10.1016/j.physb.2024.416615","url":null,"abstract":"<div><div>Fe₃GaTe₂, with intrinsic magnetism at ambient temperature and high perpendicular magnetic anisotropy, is a promising van der Waals material for 2D-materials-based spintronic devices. Herein, we report the anisotropic magnetocaloric effects and magnetic critical phenomena in Fe₃GaTe₂ single crystal. Owing to the large anisotropy, magnetic entropy change <span><math><mrow><mo>(</mo><mrow><mo>−</mo><mo>Δ</mo><msub><mi>S</mi><mi>M</mi></msub></mrow><mo>)</mo></mrow></math></span> shows anisotropic character with <span><math><mrow><mo>−</mo><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>max</mi></msubsup></mrow></math></span> of 1.67 J kg⁻¹ K⁻¹ along the <em>c</em> axis and 1.11 J kg⁻¹ K⁻¹ in the <em>ab</em> plane under field change of 5 T. The rotating <span><math><mrow><mo>Δ</mo><msub><mi>S</mi><mi>M</mi></msub></mrow></math></span> from the <em>ab</em> plane to the <em>c</em> axis reaches 0.67 J kg⁻¹ K⁻¹ at magnetic field of 5 T. By carefully fitting the <span><math><mrow><mo>−</mo><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>max</mi></msubsup></mrow></math></span> and relative cooling power (RCP), we determine their relationships to be <span><math><mrow><mo>−</mo><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>max</mi></msubsup><mo>∝</mo><msup><mi>H</mi><mi>n</mi></msup></mrow></math></span> (<em>n</em> = 0.694(1)) and <span><math><mrow><mi>R</mi><mi>C</mi><mi>P</mi><mo>∝</mo><msup><mi>H</mi><mi>m</mi></msup></mrow></math></span> (<em>m</em> = 1.301(3)) for the magnetic field along the <em>c</em>-axis. Further analysis of critical behavior near <em>T</em>_<em>C</em> reveals critical exponents <em>β</em> = 0.41(1) at <em>T</em>_<em>C</em> = 341.5(1) K, <em>γ</em> = 1.01(1) at <em>T</em>_<em>C</em> = 341.6(3) K, and <em>δ</em> = 3.67(15) at <em>T</em>_<em>C</em> = 340 K, indicating a three-dimensional complex magnetic exchange.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416615"},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442317","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":"Investigation of rare earth metal ions (Sm and Er) doped CoMoO4 polymorphs for photocatalytic dye degradation","authors":"Rahul Ragu ,&nbsp;Priyadharshini Shanmugam ,&nbsp;Moorthy Babu Sridharan ,&nbsp;Elango Muniappan ,&nbsp;Thangaraju Dheivasigamani","doi":"10.1016/j.physb.2024.416616","DOIUrl":"10.1016/j.physb.2024.416616","url":null,"abstract":"<div><div>Cobalt molybdate (CoMoO₄) and its rare earth doped variants have emerged as promising photocatalysts for degrading dye pollutants in wastewater. The photocatalysts were prepared using a modified sol-gel method, employing ammonium heptamolybdate tetrahydrate and cobalt (II) nitrate hexahydrate as precursors. The incorporation of samarium and erbium as a dopant was hypothesized to improve the photocatalytic activity of CoMoO₄ by altering its band structure and creating defect sites for improved dye adsorption and degradation. The structural and optical properties of the synthesized photocatalysts were characterized using various techniques. The photocatalytic performance of CoMoO₄, Sm:CoMoO₄ and Er:CoMoO₄ was evaluated by monitoring the degradation of MB dye under light irradiation. The results reveal that Sm:CoMoO₄ and Er:CoMoO₄ catalysts achieve a degradation efficiencies of 99 % and 97 %, respectively, highlighting the potential of rare earth-doped CoMoO₄ as an efficient photocatalyst for the remediation of dye contaminated wastewater.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416616"},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425058","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":"CBD-synthesized Mg-doped CdS thin films for hybrid solar cells and self-powered photodetectors","authors":"S. Yılmaz ,&nbsp;S.B. Töreli ,&nbsp;M. Tomakin ,&nbsp;İ. Polat ,&nbsp;E. Bacaksız","doi":"10.1016/j.physb.2024.416622","DOIUrl":"10.1016/j.physb.2024.416622","url":null,"abstract":"<div><div>Mg-doped CdS samples were deposited via chemical bath deposition onto fluorine-doped tin oxide slides with varying levels of Mg-doping. Structural analysis revealed improved crystal quality in CdS films upon Mg incorporation. Morphological examinations indicated a reduction in grain size alongside appearance of smooth, void-free surfaces particularly evident at 3 % Mg-doping. Mg-doping also resulted in enhanced transparency of CdS films, notably at 3 % and 5 % within the visible spectrum. Efficient exciton dissociation was observed in hybrid solar cells based on 1 % and 3 % Mg-doped CdS, as evidenced by photoluminescence. Top-performing solar cell achieved an efficiency of 0.220 %, nearly seven times that of control device. 5 % Mg-doped CdS-based photodetectors exhibited favorable photosensing characteristics: a responsivity of 0.011 A/W, detectivity of 4.4 × 10⁸ Jones, external quantum efficiency of 3.1 %, and rise/decay times of 26/25 ms at zero bias. These findings underscore beneficial effects of Mg-doping on both hybrid solar cell and self-driven photodetector performance.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416622"},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433778","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 nanoribbon resonant tunneling diode with dual connection between contacts","authors":"Bikramjit Basumatary ,&nbsp;Agile Mathew","doi":"10.1016/j.physb.2024.416598","DOIUrl":"10.1016/j.physb.2024.416598","url":null,"abstract":"<div><div>In this paper, we numerically study the transport properties of a resonant tunneling diode (RTD) based on graphene nanoribbon (GNR) with an H-type antidote between the contacts. The structure may also be thought of as having two parallel (W-shape) parts connecting the contacts, each having a wider channel region sandwiched between two narrower barrier regions. The energy at which quasi-bound states occur in each part depends on the dimensional parameters of the respective portion in the structure. We study how the transmission through quasi-bound states is influenced by the edge states on the contacts and dimensional parameters such as barrier length and also by the ambient temperature. The results are compared with those of an RTD with a single part connecting the contacts. Transmission peaks at different energies are observed for an RTD with asymmetrical lower and upper parts between the contacts. This is then utilized for the creation of two negative differential resistance (NDR) peaks. For numerical computation, the non-equilibrium Green’s function formalism (NEGF) based on the nearest neighbor tight-binding model is employed.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416598"},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446535","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":"Andreev reflection for MnTe altermagnet candidate","authors":"D.Yu. Kazmin,&nbsp;V.D. Esin,&nbsp;Yu.S. Barash,&nbsp;A.V. Timonina,&nbsp;N.N. Kolesnikov,&nbsp;E.V. Deviatov","doi":"10.1016/j.physb.2024.416602","DOIUrl":"10.1016/j.physb.2024.416602","url":null,"abstract":"<div><div>We experimentally study electron transport across a single planar junction between the indium electrode and MnTe altermagnet candidate. We confirm standard Ohmic behavior with strictly linear current–voltage curves above the indium critical field or temperature, although with high, about 100 kOhm, junction resistance. At low temperatures and in zero magnetic field, we observe a well-developed Andreev curve with the pronounced coherence peaks, which cannot be normally expected for these high values of normal junction resistance. The conclusion on the Andreev reflection is also supported by suppression in magnetic field, as well as by universality of the observed behavior for all of the investigated samples. The experimental results can be explained by specifics of Andreev transport through the disordered region at the superconductor-altermagnet interface. Due to a different set of restrictions on the possibility of Andreev reflection, an altermagnet suffers from the presence of disorder less than a normal spin-degenerate metal, so the conductance enhancement is retained throughout the superconducting gap.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"696 ","pages":"Article 416602"},"PeriodicalIF":2.8,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438237","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}