Finding of Bulk Ferromagnetism in Stable Organic Radical Crystal

1992 ◽  
Vol 247 ◽  
Author(s):  
Minoru Kinoshita
Keyword(s):  
Crystal Structure ◽  
Long Range ◽  
Molecular And Crystal Structure ◽  
Organic Radical ◽  
Light Elements ◽  
Nitronyl Nitroxide ◽  
Β Phase ◽  
Phase Crystal ◽  
Iupac Nomenclature ◽  
Ordered State

ABSTRACTTransition to a ferromagnetic long range ordered state was found at 0.60 K in the orthorhombic β-phase crystal of p-nitrophenyl nitronyl nitroxide (or 2-(4′-nitrophenyl)-4, 4, 5, 5-tetramethyl-4, 5-dihydro-lH-imidazol-1-oxyl-3-N-oxide in the IUPAC nomenclature). This finding provides the first example of an organic bulk ferromagnet consisting of light elements and having a definite molecular and crystal structure.

FABRICATION OF ALIGNED PIEZOELECTRIC NANOFIBER BY ELECTROSPINNING

2009 ◽  
Vol 08 (03) ◽  
pp. 231-235 ◽  
Author(s):  
MUHAMAD NASIR ◽  
MASAYA KOTAKI
Keyword(s):  
Crystal Structure ◽  
Fourier Transforms ◽  
Fiber Axis ◽  
X Ray Diffraction ◽  
Hollow Nanofibers ◽  
Scanning Calorimetry ◽  
Β Phase ◽  
Phase Crystal ◽  
Polarized Ftir ◽  
Rich Content

The aligned hollow piezoelectric poly (viniliden fluoride) (PVDF) nanofiber was prepared by co-axial electrospinning. Beaded free finer aligned hollow nanofibers have diameter range between 80 and 300 nm. Surface roughness and crystal structure of nanofiber fibers were successfully controlled by using special ionic additives. Furthermore, crystalinity of aligned fiber was evaluated by differential scanning calorimetry. Fourier transforms infra red (FTIR), polarized FTIR, and wide angle X-ray diffraction analysis of fiber showed that the aligned PVDF nanofiber had rich content β-phase crystal structure, and PVDF molecule orientation was along fiber axis. Advanced discussion will be exposed in this paper such as effect of electrospinning speeds on morphology, fiber diameter, crystalinity, and crystal structure of hollow PVDF nanofiber. Piezoelectric nanofiber has great potential application in advanced sensor and actuator.

Molecular and crystal structure of amino-substituted nitronyl nitroxide and its derivatives

2013 ◽  
Vol 54 (3) ◽  
pp. 560-565
Author(s):  
E. V. Tretyakov ◽  
G. V. Romanenko ◽  
S. E. Tolstikov ◽  
V. I. Ovcharenko
Keyword(s):  
Crystal Structure ◽  
Molecular And Crystal Structure ◽  
Nitronyl Nitroxide

Bulk ferromagnetism in the β-phase crystal of the p-nitrophenyl nitronyl nitroxide radical

1991 ◽  
Vol 186 (4-5) ◽  
pp. 401-404 ◽  
Author(s):  
Masafumi Tamura ◽  
Yasuhiro Nakazawa ◽  
Daisuke Shiomi ◽  
Kiyokazu Nozawa ◽  
Yuko Hosokoshi ◽  
...  
Keyword(s):  
Nitroxide Radical ◽  
Nitronyl Nitroxide ◽  
Nitronyl Nitroxide Radical ◽  
Β Phase ◽  
Phase Crystal

scholarly journals Molekül- und Kristallstruktur von 1.1-Dimethylsilylentitanocendichlorid, (CH3)2Si(C5H4)2TiCl2 / Molecular and Crystal Structure of l,r-Dimethylsilylene Titanocene Dichloride, (CH3)2Si(C5H4)2TiCl2

1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structure Determination ◽  
Titanocene Dichloride ◽  
Molecular And Crystal Structure ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
Space Group ◽  
X Ray ◽  
Structural Dimensions

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2

scholarly journals Structural Changes in the Acceptor Site of Photosystem II upon Ca2+/Sr2+ Exchange in the Mn4CaO5 Cluster Site and the Possible Long-Range Interactions

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 371
Author(s):  
Koua
Keyword(s):  
Crystal Structure ◽  
Photosystem Ii ◽  
Long Range ◽  
Electron Acceptor ◽  
Structural Changes ◽  
Acceptor Site ◽  
Oxygen Evolving Complex ◽  
Long Range Interactions ◽  
Structural Perturbations ◽  
Oxygen Evolving

The Mn4CaO5 cluster site in the oxygen-evolving complex (OEC) of photosystem II (PSII) undergoes structural perturbations, such as those induced by Ca2+/Sr2+ exchanges or Ca/Mn removal. These changes have been known to induce long-range positive shifts (between +30 and +150 mV) in the redox potential of the primary quinone electron acceptor plastoquinone A (QA), which is located 40 Å from the OEC. To further investigate these effects, we reanalyzed the crystal structure of Sr-PSII resolved at 2.1 Å and compared it with the native Ca-PSII resolved at 1.9 Å. Here, we focus on the acceptor site and report the possible long-range interactions between the donor, Mn4Ca(Sr)O5 cluster, and acceptor sites.

scholarly journals Incommensurately Modulated Crystal Structure and Photoluminescence Properties of Eu2O3- and P2O5-Doped Ca2SiO4 Phosphor

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Hiromi Nakano ◽  
Shota Ando ◽  
Konatsu Kamimoto ◽  
Yuya Hiramatsu ◽  
Yuichi Michiue ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Light Emission ◽  
Red Light ◽  
Basic Unit ◽  
Β Phase ◽  
Stacking Order ◽  
Cell Dimensions ◽  
Incommensurate Modulation ◽  
Unit Cell Dimensions ◽  
Identical Chemical Composition

We prepared four types of Eu2O3- and P2O5-doped Ca2SiO4 phosphors with different phase compositions but identical chemical composition, the chemical formula of which was (Ca1.950Eu3+0.013☐0.037)(Si0.940P0.060)O4 (☐ denotes vacancies in Ca sites). One of the phosphors was composed exclusively of the incommensurate (IC) phase with superspace group Pnma(0β0)00s and basic unit-cell dimensions of a = 0.68004(2) nm, b = 0.54481(2) nm, and c = 0.93956(3) nm (Z = 4). The crystal structure was made up of four types of β-Ca2SiO4-related layers with an interlayer. The incommensurate modulation with wavelength of 4.110 × b was induced by the long-range stacking order of these layers. When increasing the relative amount of the IC-phase with respect to the coexisting β-phase, the red light emission intensity, under excitation at 394 nm, steadily decreased to reach the minimum, at which the specimen was composed exclusively of the IC-phase. The coordination environments of Eu3+ ion in the crystal structures of β- and IC-phases might be closely related to the photoluminescence intensities of the phosphors.

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