The Experts below are selected from a list of 193020 Experts worldwide ranked by ideXlab platform
Vito Di Noto - One of the best experts on this subject based on the ideXlab platform.
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Single Ion conducting nanocomposite polymer electrolytes for lithium batteries based on lithiated fluorinated iron oxide and poly ethylene glycol 400
Electrochimica Acta, 2015Co-Authors: Federico Bertasi, Keti Vezzu, Enrico Negro, Graeme Nawn, Gioele Pagot, Vito Di NotoAbstract:Abstract A poly(ethylene glycol) 400 (PEG400) matrix doped with different amounts of a fluorinated Fe 2 O 3 -based nanofiller (LiFI) featuring a Li + -functIonalised surface gives rise to nanocomposite polymer electrolytes (nCPEs) that demonstrate Single-Ion conductIon. A family of nCPEs with general formula [PEG400/(LiFI) y ] and y = n Fe /n PEG400 ranging from 0 to 8.15 are prepared; they are characterized by Inductively Coupled Plasma Atomic EmissIon Spectroscopy (ICP-AES), High-ResolutIon Thermogravimetric Analysis (HR-TGA), Differential Scanning Calorimetry (DSC), and Fourier-transform vibratIonal spectroscopy in both the medium (MIR) and far (FIR) infrared. The Li + transference number, t Li+ ,is determined and Broadband Electrical Spectroscopy (BES) is used to elucidate the electrical response of the materials in terms of polarizatIon and relaxatIon events. The combinatIon of the informatIon obtained by all the aforementIoned techniques enables us to present a possible conductIon mechanism for these nCPEs Single-Ion conducting systems.
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Single Ion conducting nanocomposite polymer electrolytes based on peg400 and anIonic nanoparticles part 2 electrical characterizatIon
International Journal of Hydrogen Energy, 2014Co-Authors: Federico Bertasi, Keti Vezzu, Guinevere A Giffin, Tetiana Nosach, Paul J Sideris, S G Greenbaum, Michele Vittadello, Vito Di NotoAbstract:Abstract Molecular relaxatIon and polarizatIon phenomena of twelve Single-Ion-conducting nanocomposite polymer electrolytes (nCPEs) are studied using Broadband Electrical Spectroscopy (BES). The electrolytes are obtained by combining PEG400 oligomers with increasing amounts of anIonic nanofiller comprised of fluorinated-TiO 2 associated with Li + catIons (LiFT ® ), resulting in [PEG400/(LiFT) y ] systems with 0 ≤ y ≤ 26.4. This new class of [PEG400/(LiFT) y ] electrolytes allows us to achieve a significant Single-Ion conductivity (1.1·10 −5 S cm −1 at 30 °C for n Li / n O = 0.113) without the additIon of lithium salts. To the best of our knowledge, this is the highest conductivity value reported for this class of electrolytes. This study, in conjunctIon with the results reported in Part 1, leads us to hypothesize a conductIon mechanism in terms of two types of long-range charge-transfer processes. The first charge-transfer occurs at the interface between the filler nanoparticles and filler-PEG domains, while the second occurs through the PEG400 matrix with the assistance of polymer segmental motIon. The measured Li + transference numbers confirm that the studied materials are Single-Ion conductors.
Bingwu Wang - One of the best experts on this subject based on the ideXlab platform.
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a soft phosphorus atom to harden an erbium iii Single Ion magnet
Chemical Science, 2018Co-Authors: Shiming Chen, Jin Xiong, Qiong Yuan, Yiquan Zhang, Bingwu WangAbstract:Beyond the lanthanide organometallic Single-Ion magnet (SIM) (Cp*)Er(COT)1 ([Cp*]− = pentamethylcyclopentadienide; COT2− = cyclooctatetraenide) that has a good performance, we managed to replace one coordinated carbon atom on the [Cp*]− ring by a soft phosphorus atom and obtained (Dsp)Er(COT) (CCDC No. 1835955; Dsp− = 3,4-dimethyl-2,5-bis(trimethylsilyl)phospholyl) whose sandwich structure is reported here for the first time. This substitutIon results in a remarkable change of magnetic dynamics. It exhibits slow magnetic relaxatIon under a zero applied direct current (DC) magnetic field with an energy barrier (Δ/kB) of 358 K and magnetic hysteresis up to 9 K, both of which are higher than those of (Cp*)Er(COT). With the descended local symmetry of (Dsp)Er(COT), the energy barrier and blocking temperature (TB) both improve unexpectedly and are among the highest ones in Er(III)-based Single-molecule magnets (SMMs).
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understanding the magnetic anisotropy toward Single Ion magnets
ChemInform, 2016Co-Authors: Yinshan Meng, Bingwu Wang, Shangda Jiang, Song GaoAbstract:ConspectusSingle-molecule magnets (SMMs) can retain their magnetizatIon status preferentially after removal of the magnetic field below a certain temperature. The unique property, magnetic bistable status, enables the molecule-scale SMM to become the next-generatIon high-density informatIon storage medium. SMMs’ new applicatIons are also involved in high-speed quantum computatIon and molecular spintronics. The development of coordinatIon chemistry, especially in transitIon metal (3d) and lanthanide (4f) complexes, diversifies SMMs by introducing new ones. In both 3d and 4f SMMs, the ligands play a fundamental role in determining the SMMs’ magnetic properties. The strategies for ratIonally designing and synthesizing high-performance SMMs require a comprehensive understanding of the effects of a crystal field.In this Account, we focus mainly on the magneto-structural correlatIons of 4f or 3d Single-Ion magnets (SIMs), within which there is only one spin carrier. These one-spin carrier complexes benefit from...
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series of lanthanide organometallic Single Ion magnets
Inorganic Chemistry, 2012Co-Authors: Shangda Jiang, Bingwu Wang, Linan Zhou, Zheming WangAbstract:The synthesis, structures, and magnetic properties of a series of lanthanide organometallic mixed sandwich molecules, (Cp*)Ln(COT), are investigated, where Cp* is the pentamethylcyclopentadiene anIon and COT is the cyclooctatetraene dianIon and Ln represents TbIII, DyIII, HoIII, ErIII, and TmIII. Among the five complexes, Dy and Ho complexes are determined to be Single-Ion magnets in additIon to the previously reported Er complex. Both Dy and Ho complexes show obvious quantum tunneling magnetizatIon relaxatIon in the absence of a static field. The diluted Ho complex behaves two sets of thermally activated relaxatIon as we reported previously in Er due to the COT ring static disorder. A stair-shaped hysteresis for the Er compound can be observed at 1.6 K with Hc = 1 kOe at a sweeping rate over 700 Oe/s. The quantum tunneling decoherence relaxatIon rate increases from Er to Ho to Dy, which may be caused by the relative increase of transverse anisotropy coming from the larger tilting of the two aromatic ring...
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capping ligand perturbed slow magnetic relaxatIon in dysprosium Single Ion magnets
Chemistry: A European Journal, 2011Co-Authors: Ye Bi, Shangda Jiang, Lang Zhao, Jinkui Tang, Bingwu WangAbstract:Single-Ion magnets 1 and 2 and their diamagnetic analogues 3 and 4 for magnetic-site dilutIon were obtained through substitutIon of the coordinated water molecules of [Ln(TTA)(3)-(H(2)O)(2)] (Ln=Dy (1, 2), Y (3, 4); TTA = 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedIonate) by 2,2'-bipyridine (1, 3) and 1,10-phenanthroline (2, 4) capping ligands. Their structures and magnetic properties were investigated with the goal of identifying features relevant to modulating relaxatIon dynamics of Single-Ion magnets. The metal Ions in all complexes adopt an approximately square-antiprismatic (SAP) O(6)N(2) coordinatIon environment. The SAP polyhedrons for both 1 and 2 show slight longitudinal compressIon, while the coordinatIon sphere of 1 deviates more from an ideal SAP than that of 2, as indicated by the skew angles of the SAP environment. The similar values of U(eff) for the two magnetically diluted samples imply nearly the same distributIon of low-lying states for their Dy(III) centers, which is consistent with the slight axial contractIon observed for 1 and 2 and further corroborated by ligand-field analysis. The fast quantum tunneling rate tau(QTM) of 1, which is about ten times faster than that of 2, can presumably be associated with the larger rotatIon of the SAP surroundings. This distortIon may result in a significant transverse anisotropy terms, and thus strongly affect the dynamic behavior of the system.
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an organometallic Single Ion magnet
Journal of the American Chemical Society, 2011Co-Authors: Shangda Jiang, Bingwu Wang, Haoling Sun, Zheming Wang, Song GaoAbstract:An organometallic Single-Ion magnet is synthesized with only 19 non-hydrogen atoms featuring an erbium Ion sandwiched by two different aromatic ligands. This molecule displays a butterfly-shaped hysteresis loop at 1.8 K up to even 5 K. Alternating-current (ac) susceptibility measurement reveals the existence of two thermally activated magnetic relaxatIon processes with the energy barriers as high as 197 and 323 K, respectively.
John B Kerr - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterizatIon of network Single Ion conductors based on comb branched polyepoxide ethers and lithium bis allylmalonato borate
Macromolecules, 2006Co-Authors: John B KerrAbstract:Network Single Ion conductors (NSICs) based on comb-branch polyepoxide ethers and lithium bis(allylmalonato) borate have been synthesized and thoroughly characterized by means of Ionic conductivity measurements, electrochemical impedance, and cycling in symmetrical Li/Li half cells, Li/V6O13 full cells in which a NSIC was used as both binder and electrolyte in the cathode electrode and as the electrolyte separator membrane, and by dynamic mechanical analysis (DMA). The substitutIon of the trimethylene oxide (TMO) unit into the side chains in place of ethylene oxide (EO) units increased the polymer−Ion mobility (lower glass transitIon temperature). However, the Ionic conductivity was nearly one and half orders of magnitude lower than the corresponding pure EO-based Single Ion conductor at the same salt concentratIon, which may be ascribed to the lower dielectric constant of the TMO side chains that result in a lower concentratIon of free conducting lithium catIons. For a highly cross-linked system (EO/Li =...
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network Single Ion conductors based on comb branched polyepoxide ethers and lithium bis allylmalonato borate
Macromolecules, 2004Co-Authors: John B Kerr, Craig L ReederAbstract:Author(s): Sun, XG; Kerr, JB; Reeder, CL; Liu, G; Han, Y | Abstract: The synthesis of network Single Ion conductors to obtain Single Ion conductors with high ambient temperature conductivity and mechanical strength is discussed. The Single Ion conductors were based on comb-branched polyepoxide ethers and lithium (Li) bis(allylmelonato)borate. The Single Ion conductors possessed good mechanical strength due to the formatIon of network structure and the Li/Li symmetric cell cycling showed no concentratIon polymerizatIon. The results show that the backbone structure of the polyepoxides contributes to the total Ionic conductivity and it increases with the increasing side chain length.
Federico Bertasi - One of the best experts on this subject based on the ideXlab platform.
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Single Ion conducting nanocomposite polymer electrolytes for lithium batteries based on lithiated fluorinated iron oxide and poly ethylene glycol 400
Electrochimica Acta, 2015Co-Authors: Federico Bertasi, Keti Vezzu, Enrico Negro, Graeme Nawn, Gioele Pagot, Vito Di NotoAbstract:Abstract A poly(ethylene glycol) 400 (PEG400) matrix doped with different amounts of a fluorinated Fe 2 O 3 -based nanofiller (LiFI) featuring a Li + -functIonalised surface gives rise to nanocomposite polymer electrolytes (nCPEs) that demonstrate Single-Ion conductIon. A family of nCPEs with general formula [PEG400/(LiFI) y ] and y = n Fe /n PEG400 ranging from 0 to 8.15 are prepared; they are characterized by Inductively Coupled Plasma Atomic EmissIon Spectroscopy (ICP-AES), High-ResolutIon Thermogravimetric Analysis (HR-TGA), Differential Scanning Calorimetry (DSC), and Fourier-transform vibratIonal spectroscopy in both the medium (MIR) and far (FIR) infrared. The Li + transference number, t Li+ ,is determined and Broadband Electrical Spectroscopy (BES) is used to elucidate the electrical response of the materials in terms of polarizatIon and relaxatIon events. The combinatIon of the informatIon obtained by all the aforementIoned techniques enables us to present a possible conductIon mechanism for these nCPEs Single-Ion conducting systems.
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Single Ion conducting nanocomposite polymer electrolytes based on peg400 and anIonic nanoparticles part 2 electrical characterizatIon
International Journal of Hydrogen Energy, 2014Co-Authors: Federico Bertasi, Keti Vezzu, Guinevere A Giffin, Tetiana Nosach, Paul J Sideris, S G Greenbaum, Michele Vittadello, Vito Di NotoAbstract:Abstract Molecular relaxatIon and polarizatIon phenomena of twelve Single-Ion-conducting nanocomposite polymer electrolytes (nCPEs) are studied using Broadband Electrical Spectroscopy (BES). The electrolytes are obtained by combining PEG400 oligomers with increasing amounts of anIonic nanofiller comprised of fluorinated-TiO 2 associated with Li + catIons (LiFT ® ), resulting in [PEG400/(LiFT) y ] systems with 0 ≤ y ≤ 26.4. This new class of [PEG400/(LiFT) y ] electrolytes allows us to achieve a significant Single-Ion conductivity (1.1·10 −5 S cm −1 at 30 °C for n Li / n O = 0.113) without the additIon of lithium salts. To the best of our knowledge, this is the highest conductivity value reported for this class of electrolytes. This study, in conjunctIon with the results reported in Part 1, leads us to hypothesize a conductIon mechanism in terms of two types of long-range charge-transfer processes. The first charge-transfer occurs at the interface between the filler nanoparticles and filler-PEG domains, while the second occurs through the PEG400 matrix with the assistance of polymer segmental motIon. The measured Li + transference numbers confirm that the studied materials are Single-Ion conductors.
Mark Murrie - One of the best experts on this subject based on the ideXlab platform.
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there is nothing wrong with being soft using sulfur ligands to increase axiality in a dy iii Single Ion magnet
Chemical Communications, 2020Co-Authors: Angelos B Canaj, Sourav Dey, Oscar Cespedes, Claire Wilson, Gopalan Rajaraman, Mark MurrieAbstract:A new air-stable sulfur-ligated Dy(iii) Single-Ion magnet has been successfully isolated with Ueff = 638 K and hysteresis loops open up to 7 K. In silico studies show that the S co-ligands significantly boost the axiality and that Te- and Se-donors have the potential to further enhance the magnetic properties.
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3d Single Ion magnets
Chemical Society Reviews, 2015Co-Authors: Gavin A Craig, Mark MurrieAbstract:One of the determining factors in whether Single-molecule magnets (SMMs) may be used as the smallest component of data storage, is the size of the barrier to reversal of the magnetisatIon, Ueff. This physical quantity depends on the magnitude of the magnetic anisotropy of a complex and the size of its spin ground state. In recent years, there has been a growing focus on maximising the anisotropy generated for a Single 3d transitIon metal (TM) Ion, by an appropriate ligand field, as a means of achieving higher barriers. Because the magnetic properties of these compounds arise from a Single Ion in a ligand field, they are often referred to as Single-Ion magnets (SIMs). Here, the synthetic chemist has a significant role to play, both in the design of ligands to enforce propitious splitting of the 3d orbitals and in the judicious choice of TM Ion. Since the publicatIon of the first 3d-based SIM, which was based on Fe(II), many other contributIons have been made to this field, using different first row TM Ions, and exploring varied coordinatIon environments for the paramagnetic Ions.
