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Title: Synthesis and structural characterization of Al{sub 4}SiC{sub 4}-homeotypic aluminum silicon oxycarbide, [Al{sub 4.4}Si{sub 0.6}][O{sub 1.0}C{sub 2.0}]C

Abstract

A new quaternary layered oxycarbide, [Al{sub 4.39(5)}Si{sub 0.61(5)}]{sub S}IGMA{sub 5}[O{sub 1.00(2)}C{sub 2.00(2)}]{sub S}IGMA{sub 3}C, has been synthesized and characterized by X-ray powder diffraction, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX). The title compound was found to be hexagonal with space group P6{sub 3}/mmc, Z=2, and unit-cell dimensions a=0.32783(1) nm, c=2.16674(7) nm and V=0.20167(1) nm{sup 3}. The atom ratios Al:Si were determined by EDX, and the initial structural model was derived by the direct methods. The final structural model showed the positional disordering of one of the three types of Al/Si sites. The maximum-entropy methods-based pattern fitting (MPF) method was used to confirm the validity of the split-atom model, in which conventional structure bias caused by assuming intensity partitioning was minimized. The reliability indices calculated from the MPF were R{sub wp}=3.73% (S=1.20), R{sub p}=2.94%, R{sub B}=1.04% and R{sub F}=0.81%. The crystal was an inversion twin. Each twin-related individual was isostructural with Al{sub 4}SiC{sub 4} (space group P6{sub 3}mc, Z=2). - Graphical abstract: A new oxycarbide discovered in the Al-Si-O-C system, Al{sub 4}SiC{sub 4}-homeotypic [Al{sub 4.4}Si{sub 0.6}][O{sub 1.0}C{sub 2.0}]C. The crystal is an inversion twin, and hence the structure is represented by a split-atom model. The three-dimensional electron density distributionsmore » are determined by the maximum-entropy methods-based pattern fitting, being consistent with the disordered structural model.« less

Authors:
;  [1];  [2];  [1]
  1. Department of Environmental and Materials Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)
  2. Cooperative Research Facility Center, Toyohashi University of Technology, Toyohashi 441-8580 (Japan)
Publication Date:
OSTI Identifier:
21372532
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 183; Journal Issue: 3; Other Information: DOI: 10.1016/j.jssc.2010.01.012; PII: S0022-4596(10)00013-7; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALUMINIUM COMPOUNDS; CALCULATION METHODS; ELECTRON DENSITY; ENTROPY; HCP LATTICES; LATTICE PARAMETERS; OXYCARBIDES; SILICON COMPOUNDS; SPACE GROUPS; STRUCTURAL MODELS; SYNTHESIS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY; CARBON COMPOUNDS; COHERENT SCATTERING; CRYSTAL LATTICES; CRYSTAL STRUCTURE; DIFFRACTION; ELECTRON MICROSCOPY; HEXAGONAL LATTICES; MICROSCOPY; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SCATTERING; SPECTROSCOPY; SYMMETRY GROUPS; THERMODYNAMIC PROPERTIES

Citation Formats

Kaga, Motoaki, Iwata, Tomoyuki, Nakano, Hiromi, and Fukuda, Koichiro, E-mail: fukuda.koichiro@nitech.ac.j. Synthesis and structural characterization of Al{sub 4}SiC{sub 4}-homeotypic aluminum silicon oxycarbide, [Al{sub 4.4}Si{sub 0.6}][O{sub 1.0}C{sub 2.0}]C. United States: N. p., 2010. Web. doi:10.1016/j.jssc.2010.01.012.
Kaga, Motoaki, Iwata, Tomoyuki, Nakano, Hiromi, & Fukuda, Koichiro, E-mail: fukuda.koichiro@nitech.ac.j. Synthesis and structural characterization of Al{sub 4}SiC{sub 4}-homeotypic aluminum silicon oxycarbide, [Al{sub 4.4}Si{sub 0.6}][O{sub 1.0}C{sub 2.0}]C. United States. doi:10.1016/j.jssc.2010.01.012.
Kaga, Motoaki, Iwata, Tomoyuki, Nakano, Hiromi, and Fukuda, Koichiro, E-mail: fukuda.koichiro@nitech.ac.j. Mon . "Synthesis and structural characterization of Al{sub 4}SiC{sub 4}-homeotypic aluminum silicon oxycarbide, [Al{sub 4.4}Si{sub 0.6}][O{sub 1.0}C{sub 2.0}]C". United States. doi:10.1016/j.jssc.2010.01.012.
@article{osti_21372532,
title = {Synthesis and structural characterization of Al{sub 4}SiC{sub 4}-homeotypic aluminum silicon oxycarbide, [Al{sub 4.4}Si{sub 0.6}][O{sub 1.0}C{sub 2.0}]C},
author = {Kaga, Motoaki and Iwata, Tomoyuki and Nakano, Hiromi and Fukuda, Koichiro, E-mail: fukuda.koichiro@nitech.ac.j},
abstractNote = {A new quaternary layered oxycarbide, [Al{sub 4.39(5)}Si{sub 0.61(5)}]{sub S}IGMA{sub 5}[O{sub 1.00(2)}C{sub 2.00(2)}]{sub S}IGMA{sub 3}C, has been synthesized and characterized by X-ray powder diffraction, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX). The title compound was found to be hexagonal with space group P6{sub 3}/mmc, Z=2, and unit-cell dimensions a=0.32783(1) nm, c=2.16674(7) nm and V=0.20167(1) nm{sup 3}. The atom ratios Al:Si were determined by EDX, and the initial structural model was derived by the direct methods. The final structural model showed the positional disordering of one of the three types of Al/Si sites. The maximum-entropy methods-based pattern fitting (MPF) method was used to confirm the validity of the split-atom model, in which conventional structure bias caused by assuming intensity partitioning was minimized. The reliability indices calculated from the MPF were R{sub wp}=3.73% (S=1.20), R{sub p}=2.94%, R{sub B}=1.04% and R{sub F}=0.81%. The crystal was an inversion twin. Each twin-related individual was isostructural with Al{sub 4}SiC{sub 4} (space group P6{sub 3}mc, Z=2). - Graphical abstract: A new oxycarbide discovered in the Al-Si-O-C system, Al{sub 4}SiC{sub 4}-homeotypic [Al{sub 4.4}Si{sub 0.6}][O{sub 1.0}C{sub 2.0}]C. The crystal is an inversion twin, and hence the structure is represented by a split-atom model. The three-dimensional electron density distributions are determined by the maximum-entropy methods-based pattern fitting, being consistent with the disordered structural model.},
doi = {10.1016/j.jssc.2010.01.012},
journal = {Journal of Solid State Chemistry},
number = 3,
volume = 183,
place = {United States},
year = {Mon Mar 15 00:00:00 EDT 2010},
month = {Mon Mar 15 00:00:00 EDT 2010}
}
  • We have prepared a new layered oxycarbide, [Al{sub 5.25(5)}Si{sub 0.75(5)}][O{sub 1.60(7)}C{sub 3.40(7)}], by isothermal heating of (Al{sub 4.4}Si{sub 0.6})(O{sub 1.0}C{sub 3.0}) at 2273 K near the carbon-carbon monoxide buffer. The crystal structure was characterized using X-ray powder diffraction, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX). The title compound is trigonal with space group R3m (centrosymmetric), Z=3, and hexagonal cell dimensions a=0.32464(2) nm, c=4.00527(14) nm and V=0.36556(3) nm{sup 3}. The atom ratios Al:Si were determined by EDX, and the initial structural model was derived by the direct methods. The final structural model showed the positional disordering of one ofmore » the three types of Al/Si sites. The reliability indices were R{sub wp}=4.45% (S=1.30), R{sub p}=3.48%, R{sub B}=2.27% and R{sub F}=1.25%. The crystal is composed of three types of domains with nearly the same fraction, one of which has the crystal structure of space group R3-bar m. The crystal structure of the remaining two domains, which are related by pseudo-symmetry inversion, is noncentrosymmetric with space group R3m. - Graphical Abstract: A new aluminum silicon oxycarbide, (Al{sub 6-x}Si{sub x})(O{sub y}C{sub 5-y}) (x{approx}0.8 and y{approx}1.6). The crystal is composed of three types of domains (I, II and III), and hence the structure is represented by a split-atom model. Individual crystal structures can be regarded as layered structures, which consist of A-type [(Al,Si){sub 4}(O,C){sub 4}] unit layers and B-type [(Al,Si)(O,C){sub 2}] single layers.« less
  • A new aluminum silicon oxycarbonitride, (Al{sub 5.8}Si{sub 1.2})(O{sub 1.0}C{sub 3.5}N{sub 1.5}), has been synthesized and characterized by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS). The title compound is hexagonal with space group P6{sub 3}/mmc and unit-cell dimensions a=0.322508(4) nm, c=3.17193(4) nm and V=0.285717(6) nm{sup 3}. The atom ratios of Al:Si and those of O:C:N were, respectively, determined by EDX and EELS. The initial structural model was successfully derived from the XRPD data by the direct methods and further refined by the Rietveld method. The crystal is most probablymore » composed of four types of domains with nearly the same fraction, each of which is isotypic to Al{sub 7}C{sub 3}N{sub 3} with space group P6{sub 3}mc. The existence of another new oxycarbonitride (Al{sub 6.6}Si{sub 1.4})(O{sub 0.7}C{sub 4.3}N{sub 2.0}), which must be homeotypic to Al{sub 8}C{sub 3}N{sub 4}, has been also demonstrated by XRPD and TEM. - Graphical abstract: A new oxycarbonitride discovered in the Al-Si-O-C-N system, (Al{sub 7-x}Si{sub x})(O{sub y}C{sub z}N{sub 6-y-z}) (x{approx}1.2, y{approx}1.0 and z{approx}3.5). The crystal is composed of four types of domains (I, II, III and IV), and hence the structure is represented by a split-atom model. Individual crystal structures can be regarded as layered structures, which consist of A-type [(Al, Si){sub 4}(O, C, N){sub 4}] unit layers and B-type [(Al, Si)(O, C, N){sub 2}] single layers. Highlights: > (Al{sub 5.8}Si{sub 1.2})(O{sub 1.0}C{sub 3.5}N{sub 1.5}) as a new aluminum silicon oxycarbonitride. > Crystal structure is determined and represented by a split-atom model. > Existence of another new oxycarbonitride (Al{sub 6.6}Si{sub 1.4})(O{sub 0.7}C{sub 4.3}N{sub 2.0}) is demonstrated. > Both new materials are formed by oxidation and nitridation of (Al, Si){sub 6}(O, C){sub 5}.« less
  • A new aluminum oxycarbonitride, Al{sub 5}(O{sub x}C{sub y}N{sub 4-x-y}) (x{approx}1.4 and y{approx}2.1), has been synthesized and characterized by X-ray powder diffraction, transmission electron microscopy and electron energy loss spectroscopy (EELS). The title compound was found to be hexagonal with space group P6{sub 3}/mmc, Z=2, and unit-cell dimensions a=0.328455(6) nm, c=2.15998(3) nm and V=0.201805(6) nm{sup 3}. The atom ratios O:C:N were determined by EELS. The final structural model, which is isomorphous with that of (Al{sub 4.4}Si{sub 0.6})(O{sub 1.0}C{sub 3.0}), showed the positional disordering of one of the three types of Al sites. The maximum-entropy method-based pattern fitting (MPF) method was usedmore » to confirm the validity of the split-atom model, in which conventional structure bias caused by assuming intensity partitioning was minimized. The reliability indices calculated from the MPF were R{sub wp}=6.94% (S=1.22), R{sub p}=5.34%, R{sub B}=1.35% and R{sub F}=0.76%. The crystal was an inversion twin. Each twin-related individual was isostructural with Al{sub 5}C{sub 3}N (space group P6{sub 3}mc, Z=2). - Graphical abstract: A new oxycarbonitride discovered in the Al-O-C-N system, Al{sub 5}(O{sub 1.4}C{sub 2.1}N{sub 0.5}). The crystal is an inversion twin, and hence the structure is represented by a split-atom model. The three-dimensional electron density distributions are determined by the maximum-entropy methods-based pattern fitting, being consistent with the disordered structural model. Display Omitted« less
  • The reactions of the cis-dioxorhenium(VII)-catecholate complex [(CH{sub 3}CH{sub 2}){sub 4}N][ReO{sub 2}(O{sub 2}C{sub 6}H{sub 4}){sub 2}] (1) with either monosubstituted organohydrazines (C{sub 6}H{sub 5}NHNH{sub 2}; 4-BrC{sub 6}H{sub 4}NHNH{sub 2}) or 1,1 disubstituted organohydrazines (Ph{sub 2-}NNH{sub 2}) yield the cis-bis(diazenido) core complexes [(CH{sub 3}CH{sub 2}){sub 4}N][Re(NNR){sub 2}(O{sub 2}C{sub 6}H{sub 4}){sub 2}] (5, R = C{sub 6}H{sub 5}; 6, R = 4-BrC{sub 6}H{sub 4}) and the cis-bis(hydrazido) core species [(CH{sub 3}CH{sub 2}){sub 4}N][Re(NNPh{sub 2}){sub 2}(O{sub 2}C36H{sub 4}){sub 2}(O{sub 2}C36H{sub 4}){sub 2}] (7). Elution of 5 in a 3:1 mixture of toluene/methanol on a column of silica gel resulted in cation exchange to givemore » Na[Re(NNPh){sub 2}-(O{sub 2}C{sub 6}H{sub 4}){sub 2}]{center_dot}CH{sub 3}CN (8) as a one-dimensional polymer ([Na(CH{sub 3}CN)]{sup +}[Re(NNPh){sub 2}(O{sub 2}C{sub 6}H{sub 4}){sub 2}]{sup {minus}}){sub 2}. Crystal data for C{sub 32}H{sub 38}N{sub 5}O{sub 4}Re (5): P2{sub 1}/c,a = 14.458(3) {angstrom}, b = 10.436(2) {angstrom}, c = 21.767(4) {angstrom}, {beta} = 107.04(3){degrees}, V = 3140(2) {angstrom}{sup 3}, Z = 4, D {sub calc} = 1.572 g cm{sup {minus}3}; structure solution and refinement based on 3256 reflections with I{sub o} {ge} 3{sigma}(I{sub o}) converged at R = 0.053. Crystal data for C{sub 44}H{sub 48}N{sub 5}O{sub 4}Re (7): P1, a = 11.660(2) {angstrom}, b = 11.864(2) {angstrom}, c = 15.400(2) {angstrom}, {alpha} = 107.12(3){degrees}, {beta} = 94.99(3){degrees}, {gamma} = 97.61(3){degrees}, V = 2000(1) {angstrom}{sup 3}, Z = 2, D{sub calc} = 1.490 g cm{sup {minus}3}; 3702 reflections, R = 0.0534. Crystal data for C{sub 26}H{sub 18}N{sub 5}NaO{sub 4}Re (8): P2/n, a = 5.785(1) {angstrom}, b = 9.670(2) {angstrom}, c = 23.142(5) {angstrom}. {beta} = 90.91(30)degrees, V = 1294.4(7) {angstrom}{sup 3}, Z = 2, D{sub calc} = 1.737 g cm{sup {minus}3}; 1517 reflections, R = 0.049.« less
  • We have studied the series of nominal composition BiCu{sub 3}(Mn{sub 4−x}Fe{sub x})O{sub 12} (x=0, 1.0, 2.0) where Mn is replaced by Fe cations in the ferrimagnetic perovskite BiCu{sub 3}Mn{sub 4}O{sub 12}. These compounds have been prepared from citrate precursors under moderate pressure conditions (3.5 GPa) and 1000 °C in the presence of KClO{sub 4} as oxidizing agent. All the samples have been studied by x-ray and neutron powder diffraction (NPD) at room temperature and 4 K. The crystal structure has been defined in a cubic Im3{sup ¯} (No. 204) space group with a 2a{sub 0}×2a{sub 0}×2a{sub 0} unit-cell. The doublingmore » of the unit-cell occurs due to the ordering of Bi{sup 3+} and Cu{sup 2+} cations over A sites of the AA′{sub 3}B{sub 4}O{sub 12} structure. The A-site accommodates 12-fold coordinated Bi{sup 3+} ions and, at the A′-site, Jahn–Teller Cu{sup 2+} ions form pseudo-square planar units aligned perpendicular to each other. Mn{sup 4+}/Fe{sup 3+} cations randomly occupy the centre of slightly distorted octahedra. These materials have also been characterized by magnetic and magnetotransport measurements. We found that all the samples are ferrimagnetic and show a progressive decrease of T{sub C} as the Fe content increases, since Fe ions disturb the ferromagnetic interactions within the B magnetic sublattice. In fact, the Curie temperature diminishes from T{sub C}=360 K (x=0) to T{sub C}=219 K (x=2). The magnetic structures, studied by low-temperature NPD data, correspond to an antiferromagnetic arrangement of spins at 8c and 6b sites; the ordered moments are in excellent agreement with those obtained from the saturation magnetization at 4 K. A significant magnetoresistant effect is determined for the x=1.0 oxide, with low-field values as high as 5% at 300 K and 1 T. Highlights: • BiCu{sub 3}(Mn{sub 4−x}Fe{sub x})O{sub 12} perovskites have been prepared under high pressure conditions. • They have been characterized by NPD, magnetic and magnetotransport measures. • The introduction of Fe leads to a transition from metallic to semiconducting. • Curie temperature decreases as the Fe content increases.« less