Journal of Physics: Condensed Matter最新文献

{"title":"Robust half-metallic properties in two-dimensional CuCr₂Se₂X₂(X = Cl, Br, I).","authors":"Haimei Zhou, Yujing Guo, Shuai Liu, Yiran Peng, Wenhui Wan, Yong Liu, Yanfeng Ge","doi":"10.1088/1361-648X/adbeb0","DOIUrl":"10.1088/1361-648X/adbeb0","url":null,"abstract":"<p><p>In recent years, the rapid development of two-dimensional (2D) magnetic materials has revolutionized the field of spintronics, driven by their unique ability to combine magnetism and electronic functionality at the atomic scale. Here, we investigate the monolayer CuCr₂Se₂X₂(X = Cl, Br, I), which exhibit robust ferromagnetic (FM) behavior and half-metallicity with 100% spin polarization. The strong FM coupling, mediated by superexchange interactions, is rooted in the unique electronic structure of the Cr<i>d</i>-orbitals. Our findings reveal high Curie temperatures (TC) exceeding room temperature, with the Br variant achieving a remarkable 586 K. These exceptional properties, including the ability to modulate exchange interactions through strain engineering, highlight CuCr₂Se₂X₂as a versatile platform for flexible, high-performance spintronic devices, paving the way for advancements in next-generation electronic applications.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extended Kohler's scaling and Isosbestic point in the charge density wave state of 1T-VSe₂.","authors":"Sonika Bagga, Sunil Gangwar, Pankaj Kumar, Arghya Taraphder, C S Yadav","doi":"10.1088/1361-648X/adc6e4","DOIUrl":"https://doi.org/10.1088/1361-648X/adc6e4","url":null,"abstract":"<p><p>1T-VSe₂is a narrow band transition metal chalcogenide that shows charge density wave (CDW) state below T_CDW= 110 K. Here, we have explored the relevance of Kohler's rule and the thermal transport properties of VSe₂across the CDW state in the presence of magnetic field. The magnetoresistance (MR) follows Kohler's rule above T_CDW, while an extended Kohler's rule is employed below T_CDW. Interestingly, we observed an anomaly in MR around T ∼ 20 K, below which MR value decreases on lowering temperature. This anomaly is also reflected in the slope (κ) of Kohler's plots and the relative change in the thermal excitation induced carrier density (n_T). Despite a strong magnetic field of 14 Tesla, the T_CDWremains largely unaffected in both electrical resistivity (ρ(T)) and Seebeck coefficient (S), although the application of magnetic field does enhance the peak intensity of S around T ∼ 60 K. The crossover of S curves measured at different magnetic fields at T ∼ 20 K suggests the existence of a novel feature within the CDW state of VSe₂i.e., the presence of a locally exact isosbestic point.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of zinc oxide nano-rice decorated with silver nanoparticles for surface-enhanced Raman scattering (SERS) trace detection of isoprocarb and crystal violet.","authors":"Sy Van Vu, Kim-Dung Thi Ho, Phuong-Thao Do, Thu Anh Nguyen, Quang Duy Nguyen, Trung-Dung Tran Nguyen, Huy Huu Truong, Man Van Tran, Tien Nu Hoang Lo, In Park, Van-Nam Dao, Van-Dung Le, Khuong Quoc Vo","doi":"10.1088/1361-648X/adc05d","DOIUrl":"10.1088/1361-648X/adc05d","url":null,"abstract":"<p><p>Surface-enhanced Raman scattering (SERS) has gained substantial interest for the practical analysis of trace amounts of various molecules. However, improving the magnitude of the electromagnetic enhancement and preparing the substrate for long-term use remains top research priorities. This study presents a novel and straightforward synthesis method for zinc oxide nanorices (ZnONRs) decorated with small silver particles (Ag/ZnONR), which can serve as a highly stable, sensitive, and reproducible material for SERS detection of isoprocarb (IPC) and crystal violet (CV). Integrating ZnONR and AgNPs at an appropriate mixing ratio can generate many plasmonic 'hotspots' on the surface due to the strong surface plasmon capability of AgNPs when excited by appropriate light. The length of ZnO nanorods (ZnONR) has been controlled to range from 100 nm to 120 nm, with an aspect ratio (AR, the ratio of nanoparticle length to width) of about 3:1. Additionally, the formed silver nanoparticles have an average diameter of approximately 20-40 nm and randomly distributed on the surface of the ZnO. Specifically, we found that the exceptional detection enhancement factor was 2.5 × 10⁹, along with high reproducibility due to the embedding of AgNPs in the inert structure of ZnO nano rice, which helps prevent the loss of AgNPs during analysis and can be reused multiple times while maintaining good signal intensity stability. Significantly, this embedded nanostructure could achieve a reasonable limit of detection of 0.402 nM for CV and 0.147 pM for IPC, with a high reproducibility (RSD of 5,98%). The electromagnetic field enhancement phenomenon of this nanomaterial was further analyzed through Finite-Difference Time-Domain simulations, demonstrating that the intensity of the electromagnetic field (EM-field) of Ag/ZnONRs (66.0) is significantly ten times greater than that observed with pristine AgNPs (6.31) or ZnONRs (1.84). Integrating these nanomaterials creates a sophisticated category of hybrid nanosubstrates suitable for a wide range of future detection applications employing the SERS method.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143625053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Positron stopping in multilayer materials.","authors":"A C L Jones, T Chung, F A Selim","doi":"10.1088/1361-648X/adc062","DOIUrl":"10.1088/1361-648X/adc062","url":null,"abstract":"<p><p>Positron annihilation spectroscopy provides a sensitive toolset for defect characterization. In beam based studies of single-layer targets, the form of implantation profiles is well established, depending on the kinetic energy and angle of incident positrons relative to the target surface and the density and average atomic number of the target. For multilayer systems, the difference in density and across the layers makes derivation of an analytical form difficult. To date, the determination of positron stopping profiles in multilayer targets has primarily involved Monte Carlo simulations. We present here an alternative approach that estimates the energy distributiondN/dEof those positrons transmitted past each layer boundary, by fitting the remaining tail of the stopping profile after each layer with a basis set comprised of calculated stopping profiles in the same material they are transmitted through. The stopping profile in the next layer is then found by summing a series of stopping profiles in the new medium in proportion to the determined distributiondN/dE. The results of our model are compared with simulation results in a system of alternating layers of Al and Au and find reasonable agreement in the predicted profile and excellent agreement in the predicted mean implantation depth. Lastly, we derived a simple formula-based approach for the calculation of the mean implantation depth in two-layer systems that provides results in excellent agreement with the full model.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143625039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Phase Retrieval and Characterization of Magnetic Nanostructures via Lorentz (Scanning) Transmission Electron Microscopy.","authors":"Kayna Lee Mendoza, Haoyang Ni, Georgios Varnavides, Miaofang Chi, Colin Ophus, Amanda K Petford-Long, Charudatta Phatak","doi":"10.1088/1361-648X/adc6e3","DOIUrl":"https://doi.org/10.1088/1361-648X/adc6e3","url":null,"abstract":"<p><p>Magnetic materials phase reconstruction using Lorentz transmission electron microscopy (LTEM) measurements have traditionally been achieved using longstanding methods such as off-axis holography (OAH) fast-Fourier transform (FFT) technique and the transport-of-intensity equation (TIE). &#xD;The increase in access to processing power alongside the development of advanced algorithms have allowed for phase retrieval of nanoscale magnetic materials with greater efficacy and resolution. &#xD;Specifically, reverse-mode automatic differentiation (RMAD) and the extended electron ptychography iterative engine (ePIE) are two recent developments of phase retrieval that can be applied to analyzing micro-to-nano- scale magnetic materials. &#xD;This work evaluates phase retrieval using TIE, RMAD, and ePIE in simulations of Permalloy (Ni(_{80})Fe(_{20})) nanoscale islands, or nanomagnets. &#xD;Extending beyond simulations, we demonstrate total phase retrieval and image reconstructions of a NiFe nanowire using OAH and RMAD in LTEM and ePIE in Ltz-4D-STEM experiments and determine the saturation magnetization through corroborations with micromagnetic modeling.&#xD;Finally, we demonstrate the efficacy of these methods in retrieving the total phase and highlight its use in characterizing and analyzing the proximity effect of the magnetic nanostructures.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143743018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addendum: Microscopic dynamics and Bose-Einstein condensation in liquid helium (2023<i>J. Phys.: Condens. Matter</i>35085101).","authors":"K Trachenko","doi":"10.1088/1361-648X/adc063","DOIUrl":"https://doi.org/10.1088/1361-648X/adc063","url":null,"abstract":"<p><p>We have recently proposed that mobile transit atoms in liquid⁴He accumulate in a finite-energy state, consistent with microscopic dynamics in liquids and different types of experimental data (Trachenko 2023<i>J. Phys.: Condens. Matter</i><b>35</b>085101). Here, we point out that the superfluid transition temperature<i>T</i>_<i>λ</i>can be evaluated in this picture and is found to be within 15% of experimental<i>T</i>_<i>λ</i>.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":"37 18","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The physical origin of electric polarizations in two dimensional ferroelectric monolayer materials.","authors":"Xiao-Feng Luo, Zhuo-Peng Xia, Jin-Zhu Zhao","doi":"10.1088/1361-648X/adc6e0","DOIUrl":"https://doi.org/10.1088/1361-648X/adc6e0","url":null,"abstract":"<p><p>Over the past decade, a new class of ferroelectric materials with atomic-level thickness, particularly monolayer materials, has been predicted theoretically and confirmed experimentally. These two-dimensional ferroelectric materials, especially those exhibiting finite out-of-plane polarizations, have garnered significant attention in both condensed matter physics and materials science. On one hand, they offer promising avenues for the miniaturization of ferroelectric devices. On the other hand, they reveal novel physical mechanisms that go beyond those found in conventional bulk ferroelectrics, enabling the emergence of out-of-plane polarization under depolarization fields. Recent studies have identified various mechanisms capable of generating out-of-plane polarization in monolayers, a phenomenon previously considered unlikely in traditional bulk materials like ferroelectric perovskites. This review article highlights the recent advancements in understanding two-dimensional ferroelectricity in monolayer candidates. We focus primarily on the exploration of these unique mechanisms, as investigated and rationalized in recent years. Furthermore, we discuss the promising prospects in this emerging field of ferroelectricity and the bright future of two-dimensional monolayer materials.&#xD.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143743024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and dynamics of phytantriol-glycerol mesophases: insights into the reverse micelle to lamellar phase transition.","authors":"Matteo Rutsch, Yang Yao","doi":"10.1088/1361-648X/adbeae","DOIUrl":"10.1088/1361-648X/adbeae","url":null,"abstract":"<p><p>Lipidic mesophases (LMPs) are lyotropic liquid crystals formed by the self-assembly of lipid in water, offering diverse phase symmetries with unique physicochemical properties. However, a fundamental understanding of how the dynamics relate to the composition and structure remains limited. In this study, we substitute water with glycerol, which closely resembles the headgroup structure of phytantriol, as the solvent to explore phytantriol-based LMPs in a pure glycerol environment. The non-crystallizing nature of both phytantriol and glycerol enables phase studies at sub-zero temperatures. Combined small-angle x-ray scattering and differential scanning calorimetry analyses confirm the formation of reverse micelles (<i>L</i>₂), which undergo a phase transition to lamellar phase (<i>L_α</i>) upon cooling. Broadband dielectric spectroscopy (BDS) reveals how the dynamics of phytantriol are governed by the composition and symmetry of the LMP: increased glycerol content decreases the relaxation time of the Debye- and<i>α</i>-relaxation, therefore exerting a plasticizing effect. The change in long-range order of phytantriol during the<i>L</i>₂-<i>L_α</i>phase transition reveals a decrease of the conductivity relaxation time. The introduction of a net orientation of phytantriol further reveals a new relaxation process-the dipole-matrix interaction-exclusive to the<i>L_α</i>phase. Our results highlight the value of combining BDS with structural and thermal analyses for a deeper understanding of the dynamics in soft matter systems.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of first-cycle voltage hysteresis in Li-rich cathode materials by magnetic Compton scattering experiments.","authors":"Aierxiding Abulikemu, Tomoya Ando, Naruki Tsuji, Kosuke Suzuki, Manabu Takahashi, Tsuyoshi Takami, Hiroshi Sakurai","doi":"10.1088/1361-648X/adbf5c","DOIUrl":"https://doi.org/10.1088/1361-648X/adbf5c","url":null,"abstract":"<p><p>Lithium-rich layered oxides (LLOs) are among the most promising cathode materials for next-generation lithium-ion batteries featuring reversible capacities of 250 mAh g^-1or higher. However, LLOs suffer from severe voltage hysteresis during the charge/discharge process. In this work, we utilized magnetic Compton scattering spectroscopy to characterize the electronic states of the typical LLO Li_1.2-<i>x</i>Ni_0.2Mn_0.6O₂and extract the redox orbitals. By comparing the experimental data with the results of density functional theory calculations, we successfully achieved the first direct observation of spin-polarized oxygen 2p state modifications due to superstructural changes, which were found to be responsible for the voltage hysteresis during the charge/discharge process.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":"37 18","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of high-<i>T</i>_csuperconductivity in two corrugated graphene sheets with intercalated CeH₉molecules.","authors":"M A Rastkhadiv, M Pazoki","doi":"10.1088/1361-648X/adc061","DOIUrl":"10.1088/1361-648X/adc061","url":null,"abstract":"<p><p>Recent discoveries involving high-temperature superconductivity in H₃S and LaH₁₀have sparked a renewed interest in exploring the potential for superconductivity within hydrides. These superconductors require extremely high-pressure condition (∼100GPa), rendering them virtually impractical for industrial applications. In this study, we verify the occurrence of a low pressure superconductivity phase transition in a system containing two graphene layers with sine form corrugations where CeH₉doped molecules are intercalated between the layers. The lowest-order constrained variational method is applied to calculate the thermodynamic and electrical properties of the valence electrons. We examine 9900 different distributions of CeH₉molecules separately for finding a second-order phase transition with maximized critical temperature. The novelty of the present work is the prediction of a superconductivity transition atTc=198.61 K for a specific distribution of CeH₉molecules with applying no external pressure on the exterior surfaces of the graphene sheets. Notably, this critical temperature is approximately 65 K higher than that observed in cuprate materials (HgBa₂Ca₂Cu₃O8+δ), which are known for their highTcvalues at room pressure. It is interesting that in this particular case, the distribution periodicity of CeH₉molecules bears the closest resemblance to the periodicity of the graphene corrugations among all 9900 examined cases. Computing the energy gap of the valence electrons reveals that this critical behavior corresponds to an unconventional superconductivity phase transition exhibiting a high critical current density on the order of∼107A cm-2.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143625041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}