The Journal of Physical Chemistry C最新文献

{"title":"Deformation Mechanism of Indium Phosphide Wafers by Indenter Shape in Nanoindentation","authors":"Zilei Bai, Jiayun Deng, Xiaoning Wen, Jiacheng Geng, Hua Wei, Hanbao Liu, Feng Qiu, Feng Hui","doi":"10.1021/acs.jpcc.5c01363","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c01363","url":null,"abstract":"Molecular dynamics (MD) simulations of nanoindentation were employed to investigate the mechanical properties and elastoplastic deformation mechanisms of single-crystal indium phosphide (B3-InP) wafers oriented along the [001] crystal direction. The study examines the evolution of dislocation propagation, atomic motion, stress distribution, and strain evolution under varying indenter geometries, including Ball, Berkovich, and Vickers indenters. The results reveal that as the indentation depth increases, the pop-in phenomenon occurs first with the Ball indenter and last with the Vickers indenter, suggesting that the pop-in phenomenon is more pronounced and plastic deformation initiates more rapidly with indenters exhibiting more homogeneous stress distributions compared to those with concentrated stress distributions. Regardless of indenter shape, generated dislocations primarily consist of Shockley dislocations, with a smaller presence of perfect dislocations. These dislocations exhibit atomic displacement and slip along the ⟨110⟩ crystalline direction.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"37 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solid-State Effects on the Competition between π-Pairs and C–C σ-Dimers in Bis-1,2,3-dithiazolyl Radical-Based Materials","authors":"M. Àngels Carvajal, Ibério de P. R. Moreira, Mercè Deumal, Jordi Ribas-Ariño","doi":"10.1021/acs.jpcc.4c08781","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08781","url":null,"abstract":"The presence of either σ-dimers or π-pairs in materials based on π-radicals significantly impacts their magnetic, optical, and charge transport properties. Identifying the factors leading to σ-bonding is thus crucial. The limited occurrence of C–C σ-bonds in bisdithiazolyl-based crystals is here investigated by comparison of <i>N</i>-ethyl and <i>N</i>-methyl pyrazine-bridged derivatives through a combination of high-accuracy correlated wave function calculations in the gas phase and DFT-based periodic calculations. The σ-dimers are found to be only slightly more stable (in a range of ∼5 to ∼7 kcal mol^–1) than the corresponding π-dimers in the gas phase. This energy difference is small to compensate for the entropic cost of forming a σ-dimer, which requires specific relative orientations of the π-radicals. In addition, solid-state effects can have a strong impact on the energy difference between the two association modes. The crystal lattice of the ethyl derivative, where the electronic interaction between neighboring pairs of radicals is exceedingly small, favors σ-dimerization. Conversely, the crystal lattice of the methyl derivative hinders σ-dimerization, because the electronic localization of the unpaired π-electrons concomitant to it is constrained by the electronic interactions between neighboring pairs of radicals. These results suggest that less compact packing of the neutral radicals reduces lateral interactions, which in turn favors electron localization of the open-shell π-system to form a σ-bond if the π-stacking provides a suitable relative orientation of the radical pairs. This provides a promising scheme to stabilize single-component molecular organic materials made of neutral radical species.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"37 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Situ Cw ESR Study on Redox Behavior and Phase Heterogeneity in A-Site-Deficient Lanthanum Iron Manganite Perovskite Catalysts","authors":"Zohreh Asadi, Asghar Mohammadi, Thomas Ferdinand Winterstein, Ralf Feyerherm, Roham Talei, Nicolas Bonmassar, Wiebke Riedel, Simon Penner, Thomas Risse","doi":"10.1021/acs.jpcc.4c08262","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08262","url":null,"abstract":"Temperature-dependent <i>in situ</i> continuous wave (cw) electron spin resonance (ESR) measurements are used for investigating changes in magnetization upon reduction and reoxidation in La-deficient La_<i>x</i>Fe_0.7Mn_0.3O₃ (<i>x</i> &lt; 1) samples to advance the understanding of structural and chemical changes in these materials where A-site deficiency was shown to affect catalytic performance. For these defect-rich mixed perovskites with ferromagnetic ordering, the magnetic properties as characterized by <i>in situ</i> cw ESR spectroscopy are sensitive probes for structural changes in these materials. To this end, the ESR spectra observed in a redox cycle in H₂- and O₂-containing atmospheres not only show structural changes that were not observed by XRD but also provide evidence for heterogeneity in the magnetic phases, which notably depends on the La deficiency of the samples. This not only demonstrates the potential of such investigations for obtaining information complementary to other methods but also emphasizes the sensitivity of magnetic properties as probed by ESR to elucidate structural and chemical changes in such complex perovskite materials. While the XRD results lack indication for the presence of structural heterogeneity, STEM measurements provide evidence for a compositional heterogeneity between the grains but not for the presence of an additional magnetic phase, as observed by ESR for one of the samples. Importantly, the different magnetic phases exhibit distinct responses to reducing and (re)oxidizing atmospheres indicating for the sample with a lower La deficiency a facilitated reaction under reducing conditions at low temperatures but an overall higher structural stability. Both effects are expected to affect the reactivity in the redox reactions. Thus, these results provide new and complementary insights that can enhance the understanding of the effect of A-site deficiency in perovskite materials in redox reactions considered to be important for the catalytic activity of these systems.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"89 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stimulated Rayleigh Scattering in Plasmonic Nanofibers Doped with Metallic Nanoparticles and Quantum Dots","authors":"Mahi R Singh, Emma Caruso","doi":"10.1021/acs.jpcc.4c08427","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08427","url":null,"abstract":"A theory of stimulated Rayleigh scattering (SRS) has been developed for metallic nanohybrids made of an ensemble of metallic nanoparticles and quantum dots (QDs). The intensity of the output stimulated Rayleigh scattered light was found using the coupled-mode formalism based on Maxwell’s equations. By means of the density matrix method, it is found that the output light depends on third-order susceptibility. Analytical expressions of the intensity of the <i>electrostrictive stimulated Rayleigh scattering</i> and the <i>thermal stimulated Rayleigh scattering</i> are calculated in the presence of the surface plasmon polaritons (SPPs) and the dipole–dipole interactions (DDIs). We compared our theory with two experimental data sets for nanohybrids of this type. The first is a nanohybrid made of an ensemble of Ag nanoparticles and rhodamine 6G dye, and the second is for a nanohybrid composed of Ag nanoparticles and pyrromethene-597 dye. We found good agreement between theory and experiments. We also predicted an enhancement in the SRS intensity. The enhancement is due to the two extra scattering mechanisms of the SPP and DDI polaritons with the QDs. We also found that the SRS intensity spectrum has two peaks (i.e., maximum and minimum) at low values of the SPP and DDI couplings. However, when we increase the strength of the SPP and DDI couplings, the SRS intensity spectrum has only one peak (i.e., maximum). Finally, we can say that this type of work has never been reported in the literature. The findings of this article can be very useful. For example, the analytical expressions can be useful for experimental scientists and engineers, who can use them to compare their experiments and make new types of plasmonic devices. The enhancement of the SRS intensity can be used to fabricate SRS nanosensors. Similarly, our finding about the SRS intensity having two peaks instead of one peak due to the SPP and DDI couplings can be used to fabricate SRS nanoswitches, where the two peaks can be thought of as the ON position and the one peak can be considered as the OFF position.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"74 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon-Mediated Oxygen Vacancy Creation at Hematite Interfaces","authors":"Frances E. Zengotita, Nabajit Lahiri, Mark H. Engelhard, Maksym Zhukovskyi, Manuel R. Vejar, Kevin M. Rosso, Carolyn I. Pearce, Amy E. Hixon","doi":"10.1021/acs.jpcc.4c08423","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08423","url":null,"abstract":"Nanoscale iron oxides (e.g., hematite (α-Fe₂O₃)) have unique properties, such as enhanced chemical reactivity and high surface area, when compared with their bulk counterparts. These nanoscale surfaces can be more reactive due to the presence of defects (e.g., oxygen vacancies). In this work, we probed the surface chemistry of bulk and nanoscale hematite via X-ray photoelectron spectroscopy, electron microscopy, and powder X-ray diffraction. Oxygen exposure and vacuum annealing experiments were conducted to add or remove oxygen vacancies and remove adventitious carbon. In the absence of the oxygen annealing step, vacuum annealing resulted in partial reduction of Fe(III) to Fe(II) on all hematite surfaces. This is a size-dependent effect, with the extent of reduction increasing as the crystallite size decreases. In addition, the atomic concentrations of carbon increased on all iron oxide surfaces after vacuum annealing. Oxygen annealing almost completely removed carbon from sample surfaces, and no Fe(III) reduction was observed in the absence of carbon. Under these conditions, the results reveal that carbonaceous material enhances oxygen vacancy formation, which then facilitates the reduction of Fe(III) on hematite surfaces. We provide new insights into the mechanisms of Fe(III) reduction on both bulk and nanoscale hematite surfaces and establish the major role of carbon in oxygen vacancy formation.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"34 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Insights into Supramolecular Self-Assembly of Chiral BODIPYs toward Enhanced Chiral Optical Activity","authors":"Yurong Yang, Jiarui Li, Huacheng Li, Ziyun Jiang, Ziwei Zhou, Zhiming Wang, Bo Wang, Yang Gao, Xiang Lan","doi":"10.1021/acs.jpcc.5c01089","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c01089","url":null,"abstract":"Chiroptically active molecular materials exhibiting enhanced excitonic couplings are refreshing for organic–inorganic hybrids, molecular nanophotonics, and many other fields. Here, we synthesized multiple chiral derivatives of boron dipyrromethene (BODIPY) substituted with 1,1′-binaphthyl-2,2′-diol (BINOL). Different aromatic groups in terms of number and position were designed on the BODIPY skeleton to finely tune their supramolecular self-assembling behaviors. It was found that the chiral derivative with an anthracene group at position 8 of the BODIPY skeleton formed a helical nanofiber showing markedly sharp spectra of both absorption and circular dichroism. Intermolecular excitonic couplings lead to a significantly improved dissymmetry factor of circular dichroism and circularly polarized luminescence. Different π–π stacking interactions between the molecular components were revealed through systematic molecular designing and theoretical studies, providing insights into the self-assembling mechanism of these building blocks. These results shed light on new molecular materials development for a variety of chiral excitonic/plasmonic and optoelectronic applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"183 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superhalogen-Based Double Antiperovskite Li6NBr(BH4)2: Structural Stability and Li Ion Transport Characteristics","authors":"Tongyu Liu, Syed Jawad Hussain, Peng-Hu Du, Qiang Sun","doi":"10.1021/acs.jpcc.5c00595","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c00595","url":null,"abstract":"Antiperovskites provide an intriguing platform for designing functional materials due to their structural diversity. Especially, double antiperovskites further expand the antiperovskites family with more tunability. Going beyond atom-based double antiperovskites, superhalogens can be used to replace anions for adding more freedom of regulating properties. This study proposes superhalogen-based double antiperovskite Li₆NBr(BH₄)₂ with a unique trigonal crystal structure and dynamic stability. Li₆NBr(BH₄)₂ is found to exhibit a significant band gap of 4.40 eV with the ability to hinder the conduction of electrons. The nonspherical geometry of superhalogen BH₄ intrinsically introduces a paddle-wheel mechanism for enhancing the transport of Li⁺ ions, resulting in a Li⁺ ion conductivity of 0.54 mS/cm and an activation energy of 0.26 eV at room temperature, which outperforms its atom-based counterpart Li₆NBrBr₂ with corresponding values of 0.32 eV and 0.13 mS/cm, respectively. Furthermore, Li₆NBr(BH₄)₂ shows superior mechanical properties, including a Poisson’s ratio of 0.28 and a Pugh ratio of 1.89, indicating good ductility and flexibility, crucial for preventing cracking or delamination during battery operation.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"59 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic Strain Observation in Naturally Occurring Buckling on Twisted Bilayer Graphene: A Nano-Raman Study","authors":"Gustavo Soares, Rafael R. Barreto, Rafael Nadas, Kenji Watanabe, Takashi Taniguchi, Leonardo C. Campos, Luiz G. Cançado, Angelo Malachias","doi":"10.1021/acs.jpcc.5c00506","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c00506","url":null,"abstract":"Twisted bilayer graphene (tBG) is an exuberant electronic system, exhibiting a wide variety of electronic behaviors intricately influenced by both the twist angle and internal built-in strain. In our study, we explore how naturally occurring variations in the mismatch angle in the bilayer graphene result in localized strain gradients. These gradients are sufficient to store elastic energy, promoting deterministic buckling phenomena. Utilizing tip-enhanced Raman spectroscopy, we conducted nanometer-scale mapping of twist angle, strain distribution, and elastic energy across tBG, identifying pronounced and deterministic fluctuations in Raman peak shifts, particularly within the 2D band on wrinkled areas. This analysis enabled us to distinguish between uniaxial and biaxial strain effects and to evaluate the elastic energy that remains within these structures. Supported by finite element modeling, our results elucidate the relationship between anisotropic strain dynamics and buckling behavior, enhancing our understanding of tBG’s mechanical properties. Our findings contribute to the field of strain engineering in tBG and suggest new possibilities for tailoring the electronic and structural characteristics of these materials at the nanoscale.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"6 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to “Nano-SMSI on Bimetallic FePt Clusters”","authors":"Natalie J. Waleska-Wellnhofer, Eva Marie Freiberger, Felix Hemauer, Valentin Schwaab, Christian Papp","doi":"10.1021/acs.jpcc.5c02044","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c02044","url":null,"abstract":"This article has not yet been cited by other publications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"217 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carrier Recombination and Surface Band Bending in GaAs/InGaAs Core–Shell Nanowires with Reverse Type-I Band Alignment","authors":"Puning Wang, Bingheng Meng, Yubin Kang, Huan Liu, Xiaobing Hou, Jilong Tang, Qun Hao, Zhipeng Wei, Rui Chen","doi":"10.1021/acs.jpcc.5c01213","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c01213","url":null,"abstract":"GaAs/In<i>_<i>x</i></i>Ga_1<i>-x</i>As core–shell nanowires (NWs) with reverse type-I band alignment have attracted significant interest in optoelectronics due to their unique optical properties. However, the detailed characterizations of carrier recombination in these NWs remain insufficiently explored. In this study, GaAs/In_0.3Ga_0.7As core–shell NWs were grown via molecular beam epitaxy, and their optical properties were investigated by optical spectroscopies. For GaAs/In_0.3Ga_0.7As core–shell NWs with an 80 nm core and a 30 nm shell, the bandgap of the InGaAs shell was found to be significantly reduced by approximately 0.93 eV due to compressive strain. Power-dependent photoluminescence measurement revealed a direct transition near the band edge in the shell as well as an indirect transition associated with surface states. With an increase in temperature, the Fermi level shifts closer to the valence band, leading to band bending and a reduction in the depletion region. When the temperature exceeds 180 K, the surface-trapped carriers overcome the potential barrier, resulting in an increase in the number of direct transitions. Our results demonstrate that GaAs/InGaAs core–shell NWs with reverse type-I band alignment exhibit a strong potential for efficient photogenerated carrier extraction and collection, making them promising candidates for a wide range of optoelectronic applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"58 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}