Condensed Matter

8 pages, 2112 KiB

Open AccessArticle

Dependency of the Charge–Discharge Rate on Lithium Reaction Distributions for a Commercial Lithium Coin Cell Visualized by Compton Scattering Imaging

by Kosuke Suzuki, Ryo Kanai, Naruki Tsuji, Hisao Yamashige, Yuki Orikasa, Yoshiharu Uchimoto, Yoshiharu Sakurai and Hiroshi Sakurai

Condens. Matter 2018, 3(3), 27; https://doi.org/10.3390/condmat3030027 - 19 Sep 2018

Cited by 15 | Viewed by 3751

Abstract

In this study, lithium reaction distributions, dependent on the charge–discharge rate, were non-destructively visualized for a commercial lithium-ion battery, using the Compton scattering imaging technique. By comparing lithium reaction distributions obtained at two different charge–discharge speeds, residual lithium ions were detected at the [...] Read more.

In this study, lithium reaction distributions, dependent on the charge–discharge rate, were non-destructively visualized for a commercial lithium-ion battery, using the Compton scattering imaging technique. By comparing lithium reaction distributions obtained at two different charge–discharge speeds, residual lithium ions were detected at the center of the negative electrode in a fully discharged state, at a relatively high-speed discharge rate. Moreover, we confirmed that inhomogeneous reactions were facilitated at a relatively high-speed charge–discharge rate, in both the negative and positive electrodes. A feature of our technique is that it can be applied to commercially used lithium-ion batteries, because it uses high-energy X-rays with high penetration power. Our technique thus opens a novel analyzing pathway for developing advanced batteries. Full article

(This article belongs to the Special Issue Rechargeable Batteries Studied Using Advanced Spectroscopic and Computational Techniques)

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11 pages, 367 KiB

Open AccessArticle

Crossover Induced Electron Pairing and Superconductivity by Kinetic Renormalization in Correlated Electron Systems

by Takashi Yanagisawa, Mitake Miyazaki and Kunihiko Yamaji

Condens. Matter 2018, 3(3), 26; https://doi.org/10.3390/condmat3030026 - 6 Sep 2018

Cited by 1 | Viewed by 3029

Abstract

We investigate the ground state of strongly correlated electron systems based on an optimization variational Monte Carlo method to clarify the mechanism of high-temperature superconductivity. The wave function is optimized by introducing variational parameters in an exponential-type wave function beyond the Gutzwiller function. [...] Read more.

We investigate the ground state of strongly correlated electron systems based on an optimization variational Monte Carlo method to clarify the mechanism of high-temperature superconductivity. The wave function is optimized by introducing variational parameters in an exponential-type wave function beyond the Gutzwiller function. The many-body effect plays an important role as an origin of superconductivity in a correlated electron system. There is a crossover between weakly correlated region and strongly correlated region, where two regions are characterized by the strength of the on-site Coulomb interaction U. We insist that high-temperature superconductivity occurs in the strongly correlated region. Full article

(This article belongs to the Special Issue Selected Papers from Quantum Complex Matter 2018)

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12 pages, 1792 KiB

Open AccessArticle

The Contribution of Synchrotron Light for the Characterization of Atmospheric Mineral Dust in Deep Ice Cores: Preliminary Results from the Talos Dome Ice Core (East Antarctica)

by Giovanni Baccolo, Giannantonio Cibin, Barbara Delmonte, Dariush Hampai, Augusto Marcelli, Elena Di Stefano, Salvatore Macis and Valter Maggi

Condens. Matter 2018, 3(3), 25; https://doi.org/10.3390/condmat3030025 - 28 Aug 2018

Cited by 16 | Viewed by 4864

Abstract

The possibility of finding a stratigraphically intact ice sequence with a potential basal age exceeding one million years in Antarctica is giving renewed interest to deep ice coring operations. But the older and deeper the ice, the more impactful are the post-depositional processes [...] Read more.

The possibility of finding a stratigraphically intact ice sequence with a potential basal age exceeding one million years in Antarctica is giving renewed interest to deep ice coring operations. But the older and deeper the ice, the more impactful are the post-depositional processes that alter and modify the information entrapped within ice layers. Understanding in situ post-depositional processes occurring in the deeper part of ice cores is essential to comprehend how the climatic signals are preserved in deep ice, and consequently how to construct the paleoclimatic records. New techniques and new interpretative tools are required for these purposes. In this respect, the application of synchrotron light to microgram-sized atmospheric dust samples extracted from deep ice cores is extremely promising. We present here preliminary results on two sets of samples retrieved from the Talos Dome Antarctic ice core. A first set is composed by samples from the stratigraphically intact upper part of the core, the second by samples retrieved from the deeper part of the core that is still undated. Two techniques based on synchrotron light allowed us to characterize the dust samples, showing that mineral particles entrapped in the deepest ice layers display altered elemental composition and anomalies concerning iron geochemistry, besides being affected by inter-particle aggregation. Full article

(This article belongs to the Special Issue Condensed Matter Researches in Cryospheric Science)

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10 pages, 1138 KiB

Open AccessReview

Post-Depositional Biodegradation Processes of Pollutants on Glacier Surfaces

by Francesca Pittino, Roberto Ambrosini, Roberto S. Azzoni, Guglielmina A. Diolaiuti, Sara Villa, Isabella Gandolfi and Andrea Franzetti

Condens. Matter 2018, 3(3), 24; https://doi.org/10.3390/condmat3030024 - 11 Aug 2018

Cited by 13 | Viewed by 4715

Abstract

Glaciers are important fresh-water reservoirs for our planet. Although they are often located at high elevations or in remote areas, glacial ecosystems are not pristine, as many pollutants can undergo long-range atmospheric transport and be deposited on glacier surface, where they can be [...] Read more.

Glaciers are important fresh-water reservoirs for our planet. Although they are often located at high elevations or in remote areas, glacial ecosystems are not pristine, as many pollutants can undergo long-range atmospheric transport and be deposited on glacier surface, where they can be stored for long periods of time, and then be released into the down-valley ecosystems. Understanding the dynamics of these pollutants in glaciers is therefore important for assessing their environmental fate. To this aim, it is important to study cryoconite holes, small ponds filled with water and with a layer of sediment, the cryoconite, at the bottom, which occur on the surface of most glaciers. Indeed, these environments are hotspots of biodiversity on glacier surface as they host metabolically active bacterial communities that include generalist taxa able to degrade pollutants. In this work, we aim to review the studies that have already investigated pollutant (e.g., chlorpyrifos and polychlorinated-biphenyls (PCBs)) degradation in cryoconite holes and other supraglacial environmental matrices. These studies have revealed that bacteria play a significant role in pollutant degradation in these habitats and can be positively selected in contaminated environments. We will also provide indication for future research in this field. Full article

(This article belongs to the Special Issue Condensed Matter Researches in Cryospheric Science)

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16 pages, 1118 KiB

Open AccessArticle

Bulk Charge Ordering in the CuO₂ Plane of the Cuprate Superconductor YBa₂Cu₃O_6.9 by High-Pressure NMR

by Steven Reichardt, Michael Jurkutat, Robin Guehne, Jonas Kohlrautz, Andreas Erb and Jürgen Haase

Condens. Matter 2018, 3(3), 23; https://doi.org/10.3390/condmat3030023 - 29 Jul 2018

Cited by 14 | Viewed by 5204

Abstract

Cuprate superconductors still hold many open questions, and recently, the role of symmetry breaking electronic charge ordering resurfaced in underdoped cuprates as a phenomenon that competes with superconductivity. Here, unambiguous nuclear magnetic resonance (NMR) proof is presented for the existence of local charge [...] Read more.

Cuprate superconductors still hold many open questions, and recently, the role of symmetry breaking electronic charge ordering resurfaced in underdoped cuprates as a phenomenon that competes with superconductivity. Here, unambiguous nuclear magnetic resonance (NMR) proof is presented for the existence of local charge ordering in nearly optimally doped YBa

_{2}

Cu

_{3}

O

_{6.9}

, even up to room temperature. Increasing pressure and decreasing temperature leads to the highest degree of order in the sense that the two oxygen atoms of the unit cell of the CuO

_{2}

plane develop a charge difference of about 0.02 holes, and order throughout the whole crystal. At ambient conditions, a slightly smaller charge difference and a decreased order is found. Evidence from literature data suggests that this charge ordering is ubiquitous to the CuO

_{2}

plane of all cuprates. Thus, the role of charge ordering in the cuprates must be reassessed. Full article

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10 pages, 272 KiB

Open AccessArticle

On the Evaluation of the Spin Galvanic Effect in Lattice Models with Rashba Spin-Orbit Coupling

by Götz Seibold, Sergio Caprara, Marco Grilli and Roberto Raimondi

Condens. Matter 2018, 3(3), 22; https://doi.org/10.3390/condmat3030022 - 24 Jul 2018

Viewed by 3665

Abstract

The spin galvanic effect (SGE) describes the conversion of a non-equilibrium spin polarization into a charge current and has recently attracted renewed interest due to the large conversion efficiency observed in oxide interfaces. An important factor in the SGE theory is disorder which [...] Read more.

The spin galvanic effect (SGE) describes the conversion of a non-equilibrium spin polarization into a charge current and has recently attracted renewed interest due to the large conversion efficiency observed in oxide interfaces. An important factor in the SGE theory is disorder which ensures the stationarity of the conversion. Through this paper, we propose a procedure for the evaluation of the SGE on disordered lattices which can also be readily implemented for multiband systems. We demonstrate the performance of the method for a single-band Rashba model and compare our results with those obtained within the self-consistent Born approximation for a continuum model. Full article

(This article belongs to the Special Issue Selected Papers from Quantum Complex Matter 2018)

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9 pages, 2637 KiB

Open AccessArticle

Microdrop Deposition Technique: Preparation and Characterization of Diluted Suspended Particulate Samples

by Salvatore Macis, Giannantonio Cibin, Valter Maggi, Giovanni Baccolo, Dariush Hampai, Barbara Delmonte, Alessandro D’Elia and Augusto Marcelli

Condens. Matter 2018, 3(3), 21; https://doi.org/10.3390/condmat3030021 - 16 Jul 2018

Cited by 11 | Viewed by 4538

Abstract

The analysis of particulate matter (PM) in dilute solutions is an important target for environmental, geochemical, and biochemical research. Here, we show how microdrop technology may allow the control, through the evaporation of small droplets, of the deposition of insoluble materials dispersed in [...] Read more.

The analysis of particulate matter (PM) in dilute solutions is an important target for environmental, geochemical, and biochemical research. Here, we show how microdrop technology may allow the control, through the evaporation of small droplets, of the deposition of insoluble materials dispersed in a solution on a well-defined area with a specific spatial pattern. Using this technology, the superficial density of the deposited solute can be accurately controlled. In particular, it becomes possible to deposit an extremely reduced amount of insoluble material, in the order of few μg on a confined area, thus allowing a relatively high superficial density to be reached within a limited time. In this work, we quantitatively compare the microdrop technique for the preparation of particulate matter samples with the classical filtering technique. After having been optimized, the microdrop technique allows obtaining a more homogeneous deposition and may limit the sample amount up to a factor 25. This method is potentially suitable for many novel applications in different scientific fields such as demanding spectroscopic studies looking at the mineral fraction contained in ice cores or to pollution investigations looking at the detection of heavy metals present in ultra-trace in water. Full article

(This article belongs to the Special Issue Condensed Matter Researches in Cryospheric Science)

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10 pages, 2358 KiB

Open AccessArticle

On the Nanoscale Structure of K_xFe_2−yCh₂ (Ch = S, Se): A Neutron Pair Distribution Function View

by Panagiotis Mangelis, Hechang Lei, Marshall T. McDonnell, Mikhail Feygenson, Cedomir Petrovic, Emil S. Bozin and Alexandros Lappas

Condens. Matter 2018, 3(3), 20; https://doi.org/10.3390/condmat3030020 - 3 Jul 2018

Cited by 3 | Viewed by 4730

Abstract

Comparative exploration of the nanometer-scale atomic structure of K_xFe_2−yCh₂ (Ch = S, Se) was performed using neutron total scattering-based atomic pair distribution function (PDF) analysis of 5 K powder diffraction data in relation to physical properties. Whereas [...] Read more.

Comparative exploration of the nanometer-scale atomic structure of K_xFe_2−yCh₂ (Ch = S, Se) was performed using neutron total scattering-based atomic pair distribution function (PDF) analysis of 5 K powder diffraction data in relation to physical properties. Whereas K_xFe_2−ySe₂ is a superconductor with a transition temperature of about 32 K, the isostructural sulphide analogue is not, which instead displays a spin glass semiconducting behavior at low temperatures. The PDF analysis explores phase separated and disordered structural models as candidate descriptors of the low temperature data. For both materials, the nanoscale structure is well described by the iron (Fe)-vacancy-disordered K₂Fe_5−yCh₅ (I4/m) model containing excess Fe. An equally good description of the data is achieved by using a phase separated model comprised of I4/m vacancy-ordered and I4/mmm components. The I4/mmm component appears as a minority phase in the structure of both K_xFe_2−ySe₂ and K_xFe_2−yS₂, and with similar contribution, implying that the phase ratio is not a decisive factor influencing the lack of superconductivity in the latter. Comparison of structural parameters of the Fe-vacancy-disordered model indicates that the replacement of selenium (Se) by sulphur (S) results in an appreciable reduction in the Fe-Ch interatomic distances and anion heights, while simultaneously increasing the irregularity of FeCh₄ tetrahedra, suggesting the more significant influence of these factors. Structural features are also compared to the non-intercalated FeSe and FeS parent phases, providing further information for the discussion about the influence of the lattice degrees of freedom on the observed properties in layered iron chalcogenides. Full article

(This article belongs to the Special Issue Complex Nanoscale Geometry and Dynamics at the Frontier between Biology and Material Science)

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Condens. Matter, Volume 3, Issue 3 (September 2018) – 8 articles

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