Showing papers by "Jun Lu published in 2013"
TL;DR: New two-dimensional niobium and vanadium carbides have been synthesized by selective etching, at room temperature, of Al from Nb2 AlC and V2AlC, demonstrating good capability to handle high charge-discharge rates.
Abstract: New two-dimensional niobium and vanadium carbides have been synthesized by selective etching, at room temperature, of Al from Nb2AlC and V2AlC, respectively. These new matrials are promising electrode materials for Li-ion batteries, demonstrating good capability to handle high charge–discharge rates. Reversible capacities of 170 and 260 mA·h·g–1 at 1 C, and 110 and 125 mA·h·g–1 at 10 C were obtained for Nb2C and V2C-based electrodes, respectively.
1,444 citations
TL;DR: The complete, thin Li(2)TiO(3) coating layer strongly adheres to the host material and has a 3D diffusion path for Li(+) ions.
Abstract: By using a novel coating approach based on the reaction between MC(2)O(4)·xH(2)O and Ti(OC(4)H(9))(4), a series of nanoscale Li(2)TiO(3)-coated LiMO(2) nanobelts with varied Ni, Co, and Mn contents was prepared for the first time. The complete, thin Li(2)TiO(3) coating layer strongly adheres to the host material and has a 3D diffusion path for Li(+) ions. It is doped with Ni(2+) and Co(3+) ions in addition to Ti(4+) in LiMO(2), both of which were found to favor Li(+)-ion transfer at the interface. As a result, the coated nanobelts show improved rate, cycling, and thermal capabilities when used as the cathode for Li-ion battery.
226 citations
TL;DR: It is demonstrated that microRNA-30c is transcriptionally regulated by GATA3 in breast tumours and inversely correlates with interleukin-11 expression in primary breast tumour patients, and low interleuko-11 correlates with relapse-free survival in breast cancer patients.
Abstract: Chemotherapy resistance frequently drives tumour progression. However, the underlying molecular mechanisms are poorly characterized. Epithelial-to-mesenchymal transition has been shown to correlate with therapy resistance, but the functional link and signalling pathways remain to be elucidated. Here we report that microRNA-30c, a human breast tumour prognostic marker, has a pivotal role in chemoresistance by a direct targeting of the actin-binding protein twinfilin 1, which promotes epithelial-to-mesenchymal transition. An interleukin-6 family member, interleukin-11 is identified as a secondary target of twinfilin 1 in the microRNA-30c signalling pathway. Expression of microRNA-30c inversely correlates with interleukin-11 expression in primary breast tumours and low interleukin-11 correlates with relapse-free survival in breast cancer patients. Our study demonstrates that microRNA-30c is transcriptionally regulated by GATA3 in breast tumours. Identification of a novel microRNA-mediated pathway that regulates chemoresistance in breast cancer will facilitate the development of novel therapeutic strategies.
223 citations
TL;DR: The influence of oxygen crossover from the cathode to the anode on electrolyte, and lithium anode, decomposition in ether-based Li-O(2) batteries is investigated.
Abstract: Crosstown traffic: Further development of Li-O(2) batteries may eventually lead to their use in transportation applications. One problem that needs to be addressed is electrolyte decomposition, which has been partially mitigated by using ether- rather than carbonate-based solvents. The influence of oxygen crossover from the cathode to the anode on electrolyte, and lithium anode, decomposition in ether-based Li-O(2) batteries is investigated.
220 citations
TL;DR: Patient-specific iPSC-derived cardiomyocytes display key features of ARVC, including reduced cell surface localization of desmosomal proteins and a more adipogenic phenotype.
Abstract: Aims Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary heart muscle disorder associated with sudden cardiac death. Its pathophysiology is still poorly understood. We aimed to produce an in vitro cellular model of ARVC using patient-specific induced pluripotent stem cell (iPSC)-derived cardiomyocytes and determine whether the model could recapitulate key features of the disease phenotype.
Methods and results Dermal fibroblasts were obtained from a 30-year-old man with a clinical diagnosis of ARVC, harbouring a plakophilin 2 (PKP2) gene mutation. Four stable iPSC lines were generated using retroviral reprogramming, and functional cardiomyocytes were derived. Gene expression levels of desmosomal proteins (PKP2 and plakoglobin) in cardiomyocytes from ARVC–iPSCs were significantly lower compared with cardiomyocytes from control iPSCs ( P < 0.01); there were no significant differences in the expression of desmoplakin, N -cadherin, and connexin 43 between the two groups. Cardiomyocytes derived from ARVC–iPSCs exhibited markedly reduced immunofluorescence signals when stained for PKP2 and plakoglobin, but similar levels of staining for desmoplakin, N -cadherin, and connexin 43 compared with control cardiomyocytes. Transmission electron microscopy showed that ARVC–iPSC cardiomyocytes were larger and contained darker lipid droplets compared with control cardiomyocytes. After 2 weeks of cell exposure to adiopgenic differentiation medium, ARVC–iPSC cardiomyocytes were found to contain a significantly greater amount of lipid, calculated using Oil Red O staining, compared with controls (734 ± 35.6 vs. 8.1 ± 0.49 a.u., respectively; n = 7, P = 0.001).
Conclusion Patient-specific iPSC-derived cardiomyocytes display key features of ARVC, including reduced cell surface localization of desmosomal proteins and a more adipogenic phenotype.
201 citations
TL;DR: It is shown that sporophyll maturation of U. pinnatifida in New Zealand influenced fucoidan content and composition, which could potentially be a good resource for natural antioxidants.
188 citations
TL;DR: Processed NZ U. pinnatifida had a lower fucoxanthin content and antioxidant activity than freeze-dried Undaria, and commercial wakame from Japan and Korea were further compared.
187 citations
TL;DR: This is the first example of T-cell regulation through systemic transit of exosome-like nanovesicles delivering a chosen inhibitory miRNA to target effector T cells in an antigen-specific manner by a surface coating of antibody light chains.
Abstract: Background T-cell tolerance of allergic cutaneous contact sensitivity (CS) induced in mice by high doses of reactive hapten is mediated by suppressor cells that release antigen-specific suppressive nanovesicles. Objective We sought to determine the mechanism or mechanisms of immune suppression mediated by the nanovesicles. Methods T-cell tolerance was induced by means of intravenous injection of hapten conjugated to self-antigens of syngeneic erythrocytes and subsequent contact immunization with the same hapten. Lymph node and spleen cells from tolerized or control donors were harvested and cultured to produce a supernatant containing suppressive nanovesicles that were isolated from the tolerized mice for testing in active and adoptive cell-transfer models of CS. Results Tolerance was shown due to exosome-like nanovesicles in the supernatants of CD8 + suppressor T cells that were not regulatory T cells. Antigen specificity of the suppressive nanovesicles was conferred by a surface coat of antibody light chains or possibly whole antibody, allowing targeted delivery of selected inhibitory microRNA (miRNA)–150 to CS effector T cells. Nanovesicles also inhibited CS in actively sensitized mice after systemic injection at the peak of the responses. The role of antibody and miRNA-150 was established by tolerizing either panimmunoglobulin-deficient JH −/− or miRNA-150 −/− mice that produced nonsuppressive nanovesicles. These nanovesicles could be made suppressive by adding antigen-specific antibody light chains or miRNA-150, respectively. Conclusions This is the first example of T-cell regulation through systemic transit of exosome-like nanovesicles delivering a chosen inhibitory miRNA to target effector T cells in an antigen-specific manner by a surface coating of antibody light chains.
179 citations
TL;DR: In this article, porous carbon-supported MnO2 nanorods synthesized at room temperature were explored as an electrocatalyst for rechargeable Li-O2 cells, with a capacity of ∼1400 mA h g−1 (carbon + electrocatalysts) under a current density of 100 mA g −1 during the initial discharge.
Abstract: Lithium–O2 cells can be considered the “holy grail” of lithium batteries because they offer much superior theoretical energy density to conventional lithium-ion systems. In this study, porous carbon-supported MnO2 nanorods synthesized at room temperature were explored as an electrocatalyst for rechargeable Li–O2 cells. Both high-energy X-ray diffraction and X-ray absorption fine-structure analyses showed that the prepared MnO2 exhibited a tetragonal crystal structure (α-MnO2), which has proved to be one of the most efficient catalysts to facilitate the charging of the Li–O2 cell. Under the current synthetic approach, α-MnO2 was uniformly distributed onto the surface of a carbon support, without disrupting the porous structure at the surface of the carbon cathode. As a result, the as-prepared catalysts demonstrated good electrochemical behavior, with a capacity of ∼1400 mA h g−1 (carbon + electrocatalyst) under a current density of 100 mA g−1 (carbon + electrocatalyst) during the initial discharge. The charge potential was significantly reduced, to 3.5–3.7 V, compared with most of the reported data, which are above 4.0 V. The mechanism of the capacity fade with cycling was also investigated by analyzing the cathode at different states of discharge–charge by X-ray photoelectron spectroscopy.
178 citations
TL;DR: In this paper, atomic layer deposition (ALD) was used to deposit nanostructured palladium on porous carbon as the cathode material for Li-O2 cells, where discrete crystalline nanoparticles decorated the surface of the porous carbon support, where the size could be controlled in the range of 2-8 nm and depended on the number of Pd ALD cycles performed.
Abstract: In this study, atomic layer deposition (ALD) was used to deposit nanostructured palladium on porous carbon as the cathode material for Li–O2 cells. Scanning transmission electron microscopy showed discrete crystalline nanoparticles decorating the surface of the porous carbon support, where the size could be controlled in the range of 2–8 nm and depended on the number of Pd ALD cycles performed. X-ray absorption spectroscopy at the Pd K-edge revealed that the carbon supported Pd existed in a mixed phase of metallic palladium and palladium oxide. The conformality of ALD allowed us to uniformly disperse the Pd catalyst onto the carbon support while preserving the initial porous structure. As a result, the charging and discharging performance of the oxygen cathode in a Li–O2 cell was improved. Our results suggest that ALD is a promising technique for tailoring the surface composition and structure of nanoporous supports in energy storage devices.
170 citations
TL;DR: It is demonstrated that hiPSC-CMs derived from a LQT3 patient recapitulate the biophysical abnormalities that define LQM3, and the clinical significance of such an in vitro model is in the development of novel therapeutic strategies and a more personalized approach in testing drugs on patients with L QT3.
TL;DR: In this paper, a novel cathode material based on lithium-nickel-manganese-cobalt oxide, where the manganese concentration remains constant throughout the particle, while the nickel concentration decreases linearly and the cobalt concentration increases from the center to the outer surface of the particle.
Abstract: We have developed a novel cathode material based on lithium–nickel–manganese–cobalt oxide, where the manganese concentration remains constant throughout the particle, while the nickel concentration decreases linearly and the cobalt concentration increases from the center to the outer surface of the particle. This full concentration gradient material with a fixed manganese composition (FCG–Mn-F) has an average composition of Li[Ni0.60Co0.15Mn0.25]O2 and is composed of rod-shaped primary particles whose length reaches 2.5 μm, growing in the radial direction. In cell tests, the FCG–Mn-F material delivered a high capacity of 206 mAh g–1 with excellent capacity retention of 70.3% after 1000 cycles at 55 °C. This cathode material also exhibited outstanding rate capability, good low-temperature performance, and excellent safety, compared to a conventional cathode having the same composition (Li[Ni0.60Co0.15Mn0.25]O2), where the concentration of the metals is constant across the particles.
TL;DR: A series of Ti-based intermetallic alloy (TiAl, Ti3Al,TiNi, TiFe, TiNb, TiMn2, and TiVMn)-doped MgH2 materials were systematically investigated in this paper to improve its hydrogen storage properties.
Abstract: Magnesium hydride is a promising candidate for solid-state hydrogen storage and thermal energy storage applications. A series of Ti-based intermetallic alloy (TiAl, Ti3Al, TiNi, TiFe, TiNb, TiMn2, and TiVMn)-doped MgH2 materials were systematically investigated in this study to improve its hydrogen storage properties. The dehydrogenation and hydrogenation properties were studied by using both thermogravimetric analysis and pressure–composition–temperature (PCT) isothermal to characterize the temperature of dehydrogenation and the kinetics of both desorption and absorption of hydrogen by these doped MgH2. Results show significant improvements of both dehydrogenation and hydrogenation kinetics as a result of adding the Ti intermetallic alloys as catalysts. In particular, the TiMn2-doped Mg demonstrated extraordinary hydrogen absorption capability at room temperature and 1 bar hydrogen pressure. The PCT experiments also show that the hydrogen equilibrium pressures of MgH2 were not affected by these additives.
TL;DR: It is shown that TET2 is under extensive microRNA (miRNA) regulation, and such TET1 targeting is an important pathogenic mechanism in hematopoietic malignancies, and the work suggests that Tet2-targeting miRNAs might be exploited in cancer diagnosis.
TL;DR: In this paper, a tin sulfide nanobelts with a length/thickness ratio of 100 have been synthesized by a facile hydrothermal method without any surfactants, and they have shown good strain-accommodating properties as well as good electrochemical performance as the anode for Li-ion batteries.
Abstract: [020]-oriented tin sulfide nanobelts with a length/thickness ratio of 100 have been synthesized by a facile hydrothermal method without any surfactants, and the nanobelts have shown good strain-accommodating properties as well as good electrochemical performance as the anode for Li-ion batteries. The formation of the nanobelts results from a precipitation-dissolution-transformation mechanism, and the [020] oriented growth can be ascribed to the {010} facet family having the lowest atomic density. In particular, SnS shows clear Li-Sn alloying/de-alloying reversible reactions in the potential range 0.1–1.0 V. Based on galvanostatic measurements and electrochemical impedance spectroscopy, SnS nanobelts have shown impressive rate performance. The post-cycled SnS nanobelts were completely transformed into metallic tin, and preserved the one-dimensional structure due to their flexibility which accommodates the large volumetric expansion.
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TL;DR: A microRNA screen of primary Wilms' tumors identified specific overexpression of miR-483-5p, which is embedded within the IGF2 gene, and observations suggest a functional positive feedback loop of an intronic miRNA on transcription of its host gene.
Abstract: Insulin-like growth factor 2 (IGF2), a developmentally regulated and maternally imprinted gene, is frequently overexpressed in pediatric cancers. Although loss of imprinting (LOI) at fetal promoters contributes to increased IGF2 in tumors, the magnitude of IGF2 expression suggests the involvement of additional regulatory mechanisms. A microRNA (miRNA) screen of primary Wilms' tumors identified specific overexpression of miR-483-5p, which is embedded within the IGF2 gene. Unexpectedly, the IGF2 mRNA itself is transcriptionally up-regulated by miR-483-5p. A nuclear pool of miR-483-5p binds directly to the 5′ untranslated region (UTR) of fetal IGF2 mRNA, enhancing the association of the RNA helicase DHX9 to the IGF2 transcript and promoting IGF2 transcription. Ectopic expression of miR-483-5p in IGF2-dependent sarcoma cells is correlated with increased tumorigenesis in vivo. Together, these observations suggest a functional positive feedback loop of an intronic miRNA on transcription of its host gene.
TL;DR: In this article, six LiFePO4 nanocrystals with different size and shape have been successfully synthesized in ethylene glycol, and the addition sequence Fe-PO4-Li helps to form LiFeP4 nanocysstals with mostly {010} faces exposed, and increasing the amount of LiOH leads to a decrease in particle size.
Abstract: Lithium iron phosphate (LiFePO4) is a potential high efficiency cathode material for lithium ion batteries, but the low electronic conductivity and single diffusion channel for lithium ions require good particle size and shape control during the synthesis of this material. In this paper, six LiFePO4 nanocrystals with different size and shape have been successfully synthesized in ethylene glycol. The addition sequence Fe-PO4-Li helps to form LiFePO4 nanocrystals with mostly {010} faces exposed, and increasing the amount of LiOH leads to a decrease in particle size. The electrochemical performance of the six distinct LiFePO4 particles show that the most promising LiFePO4 nanocrystals either have predominant {010} face exposure or high specific area, with little iron(II) oxidation.
TL;DR: In this paper, it has been shown that employing an α-MnO2/ramsdellite-mnO 2 electrode/electrocatalyst results in the formation of lithium-oxide-like discharge products in propylene carbonate, which has been reported to be extremely susceptible to decomposition.
Abstract: It has become clear that cycling lithium-oxygen cells in carbonate electrolytes is impractical, as electrolyte decomposition, triggered by oxygen reduction products, dominates the cell chemistry. This research shows that employing an α-MnO2/ramsdellite-MnO2 electrode/electrocatalyst results in the formation of lithium-oxide-like discharge products in propylene carbonate, which has been reported to be extremely susceptible to decomposition. X-ray photoelectron data have shown that what are likely lithium oxides (Li2O2 and Li2O) appear to form and decompose on the air electrode surface, particularly at the MnO2 surface, while Li2CO3 is also formed. By contrast, cells without α-MnO2/ramsdellite-MnO2 fail rapidly in electrochemical cycling, likely due to the differences in the discharge product. Relatively high electrode capacities, up to 5000 mAh/g (carbon + electrode/electrocatalyst), have been achieved with non-optimized air electrodes. Insights into reversible insertion reactions of lithium, lithium peroxide (Li2O2) and lithium oxide (Li2O) in the tunnels of α-MnO2, and the reaction of lithium with ramsdellite-MnO2, as determined by first principles density functional theory calculations, are used to provide a possible explanation for some of the observed results. It is speculated that a Li2O-stabilized and partially-lithiated electrode component, 0.15Li2O·α-LixMnO2, that has Mn4+/3+ character may facilitate the Li2O2/Li2O discharge/charge chemistries providing dual electrode/electrocatalyst functionality.
TL;DR: Hardness is an essential property for a wide range of applications as discussed by the authors, however, hardness alone, typically accompanied by brittleness, is not sufficient to prevent failure in ceramic films exposed to h...
Abstract: Hardness is an essential property for a wide range of applications. However, hardness alone, typically accompanied by brittleness, is not sufficient to prevent failure in ceramic films exposed to h ...
TL;DR: Results of this research showed that MgH2 can indeed be destabilized by forming solid solution alloys of magnesium with group III and IVB elements, such as indium, and the equilibrium hydrogen pressure of a Mg-0.1In alloy is 70% higher than that of pure Mg H2.
Abstract: Efforts to thermodynamically destabilize magnesium hydride (MgH2), so that it can be used for practical hydrogen storage applications, have been a difficult challenge that has eluded scientists for decades. This letter reports that MgH2 can indeed be destabilized by forming solid solution alloys of magnesium with group III and IVB elements, such as indium. Results of this research showed that the equilibrium hydrogen pressure of a Mg–0.1In alloy is 70% higher than that of pure MgH2. The temperature at 1 bar hydrogen pressure (T1bar) of Mg–0.1In alloy was reduced to 262.9 °C from 278.9 °C, which is the T1bar of pure MgH2. Furthermore, the kinetic rates of dehydrogenation of Mg–0.1In alloy hydride doped with a titanium intermetallic (TiMn2) catalyst were also significantly improved compared with those of MgH2.
TL;DR: The relative recovery of motor function during REM sleep in some of the cases of PD with RBD emphasizes the complexity of motor pathway control during wakefulness and REM sleep.
TL;DR: Evidence is provided that the stability of the electrolyte used in Li-O2 cells strongly depends on the compatibility of lithium salts with solvent and the decomposition of LiPF6 occurs in the cell as evidenced by in situ XRD, FT-IR and XPS analysis.
Abstract: The stability of lithium salts, especially in the presence of reduced oxygen species, O2 and H2O (even in a small amount), plays an important role in the cyclability and capacity of Li–O2 cells. This combined experimental and computational study provides evidence that the stability of the electrolyte used in Li–O2 cells strongly depends on the compatibility of lithium salts with solvent. In the case of the LiPF6–1NM3 electrolyte, the decomposition of LiPF6 occurs in the cell as evidenced by in situ XRD, FT-IR and XPS analysis, which triggers the decomposition of 1NM3 solvent due to formation of HF from the decomposition of LiPF6. These reactions lead to degradation of the electrolyte and cause poor cyclability of the cell. The same reactions are not observed when LiTFSI and LiCF3SO3 are used as the lithium salts in 1NM3 solvent, or LiPF6 is used in TEGDME solvent.
TL;DR: The new nanoindentation approach provides a straightforward method to characterize piezoelectric material deposited on flexible and disposable substrates for the next generation of nanodevices.
Abstract: We report the piezoelectric properties of ZnO nanowires (NWs) obtained by using a nanoindenter with a conductive boron-doped diamond tip. The direct piezoelectric effect was measured by performing nanoindentations under load control, and the generated piezoelectric voltage was characterized as a function of the applied loads in the range 0.2–6 mN. The converse piezoelectric effect was measured by applying a DC voltage to the sample while there was a low applied force to allow the tip being always in physical contact with the NWs. Vertically aligned ZnO NWs were grown on inexpensive, flexible, and disposable paper substrates using a template-free low temperature aqueous chemical growth method. When using the nanoindenter to measure the direct piezoelectric effect, piezopotential values of up to 26 mV were generated. Corresponding measurement of the converse piezoelectric effect gave an effective piezoelectric coefficient deff33 of ∼9.2 pm V−1. The ZnO NWs were also characterized using scanning electron microscopy, X-ray diffraction, and high-resolution transmission electron microscopy. The new nanoindentation approach provides a straightforward method to characterize piezoelectric material deposited on flexible and disposable substrates for the next generation of nanodevices.
TL;DR: The Pt3Ni/rGO nanocatalysts exhibited improved catalytic activity and durability and a simple in situ reduction approach was used to obtain Pt-Ni/reduced graphene oxide (rGO) with dominant {111} facets.
TL;DR: In this article, a core-shelled Fe/Fe3O4 nanocomposite on porous carbon was synthesized via a wet-chemistry approach, which was tested as a cathode material in rechargeable Li-O2 battery, showing highly active catalytic effect towards the electrochemical reactions, of particular, oxygen reduction reaction.
Abstract: Uniformly dispersed core-shelled Fe/Fe3O4 nanocomposite on porous carbon was synthesized via a wet-chemistry approach, which was tested as a cathode material in rechargeable Li–O2 battery, showing highly active catalytic effect towards the electrochemical reactions, of particular, oxygen reduction reaction. XPS data showed the oxygen reduction reaction took place on the surface of the catalyst during discharge of the cell. Both XRD and XPS data demonstrated that lithium peroxide partook in the reversible reactions in the Li–O2 cell with a TEGDME-based electrolyte.
TL;DR: In this article, the authors focus on the research activities on rechargeable non-aqueous Li-air batteries at Argonne National Laboratory, with the emphasis on the gains in understanding of electrolyte decomposition, the structure and magnetic properties of lithium peroxide (Li2O2), development of an air-breathing cathode, and the effect of oxygen crossover on the lithium anode.
Abstract: Rechargeable non-aqueous Li-air battery technology offers potential advantages over other existing battery systems in terms of specific energy and energy density, which could enable the driving range of an electric vehicle to be comparable to that of gasoline vehicles. Development of efficient cathode catalysts and stable electrolytes for the Li-air battery has been intensively investigated for the past several years, and a number of review articles covering different topics are already available. This review mainly focuses on the research activities on rechargeable non-aqueous Li-air batteries at Argonne National Laboratory, with the emphasis on the gains in understanding of electrolyte decomposition, the structure and magnetic properties of lithium peroxide (Li2O2), development of an air-breathing cathode, and the effect of oxygen crossover on the lithium anode. Insights from this research have led to the improvement of the electrochemical performance of Li-air batteries. Promising paths for future work on rechargeable Li-air batteries are also discussed.
TL;DR: In this paper, the locations of the Al2O3 clusters are related to the migration of Al atoms diffusing out of Ti2AlC. This mechanism is explained by the microstructure-dependent oxidation mechanism.
Abstract: Ti2AlC thin films deposited onto Al2O3 by magnetron sputtering were used as model for studying the early stages ( ( 1 0 1 ¯ 3 ) and ( 1 0 1 ¯ 6 ) as shown by X-ray diffraction and s electron microscopy. During oxidation, Al2O3 clusters and areas of C-containing titania (TiOxCy) are formed on the surface. A mechanism is proposed in which the locations of the Al2O3 clusters are related to the migration of Al atoms diffusing out of Ti2AlC. The Al2O3 is initially formed in valleys or on plateaus where Al atoms have been trapped while TiOxCy forms by in-diffusion of oxygen into the Al-deficient Ti2AlC. At 500 °C, the migration of Al atoms is faster than the oxidation kinetics; explaining this microstructure-dependent oxidation mechanism.
TL;DR: In this paper, three separate magnetrons with elemental targets were placed on Si wafer substrates and the substrate was moved in a circular motion such that the substrate faces each magnetron in turn and only one atomic species (Ti, Si or C) was deposited at a time.
TL;DR: The observed ferromagnetic interfacial coupling is supported by ab initio density functional calculations and may provide a viable pathway for designing room-temperature semiconductor spintronic devices through magnetic proximity effect.
Abstract: The magnetic properties of a Co2FeAl/(Ga,Mn)As bilayer epitaxied on GaAs (001) are studied both experimentally and theoretically. Unlike the common antiferromagnetic interfacial interaction existing in most ferromagnet-magnetic semiconductor bilayers, a ferromagnetic interfacial interaction in the Co2FeAl/(Ga,Mn)As bilayer is observed from measurements of magnetic hysteresis and x-ray magnetic circular dichroism. The Mn ions in a 1.36 nm thick (Ga,Mn)As layer remain spin polarized up to 400 K due to the magnetic proximity effect. The minor loops of the Co2FeAl/(Ga,Mn)As bilayer shift with a small ferromagnetic interaction field of +24 Oe and -23 Oe at 15 K. The observed ferromagnetic interfacial coupling is supported by ab initio density functional calculations. These findings may provide a viable pathway for designing room-temperature semiconductor spintronic devices through magnetic proximity effect.
TL;DR: In this article, the synthesis of well aligned and highly dense polyethylene glycol template assisted cupric oxide (CuO) nanoleaves on the gold coated glass substrate by hydrothermal growth method was described.
Abstract: The present study describes the synthesis of well aligned and highly dense polyethylene glycol template assisted cupric oxide (CuO) nanoleaves on the gold coated glass substrate by hydrothermal growth method. The structural study based investigations of CuO nanoleaves were performed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), infrared reflection-absorption spectroscopy (IRAS), and high resolution transmission electron microscopy (HRTEM). The glucose sensor based on the glucose oxidase immobilized CuO nanoleaves electrode detected the wide range of glucose concentrations with good linearity and exhibited high sensitivity of 61.9 ± 2.0 mV/decade. The linear detection range was observed from 1.0 × 10−5 to 2.0 × 10−2 M with detection limit of 5.0 × 10−6 M and a fast response time of less than 5 s was also observed. The glucose sensor electrode possesses good anti-interference ability, stability, repeatability, and reproducibility.