scholarly journals Analysis of isothermal sintering of zinc-titanate doped with MgO

2007 ◽  
Vol 39 (3) ◽  
pp. 241-248 ◽  
Author(s):  
N. Obradovic ◽  
S. Stevanovic ◽  
M. Mitric ◽  
M.V. Nikolic ◽  
M.M. Ristic
Keyword(s):  
Crystal Structure ◽  
Mechanical Activation ◽  
Structural Characterization ◽  
Ball Mill ◽  
Room Temperature ◽  
Zinc Titanate ◽  
Different Temperatures ◽  
Doped Zno ◽  
Titanate Ceramics

The aim of this work was analysis of isothermal sintering of zinc titanate ceramics doped with MgO obtained by mechanical activation. Mixtures of ZnO, TiO2 and MgO (0, 1.25 and 2.5%) were mechanically activated 15 minutes in a planetary ball mill. The powders obtained were pressed under different pressures and the results were fitted with a phenomenological compacting equation. Isothermal sintering was performed in air for 120 minutes at four different temperatures. Structural characterization of ZnO-TiO2-MgO system after milling was performed at room temperature using XRPD measurements. DTA measurements showed different activation energies for pure and doped ZnO-TiO2 systems. Thus addition of MgO stabilizes the crystal structure of zinc titanate.

scholarly journals Sintering of mechanically activated magnesium-titanate and barium-zinc-titanate ceramics

2011 ◽  
Vol 43 (2) ◽  
pp. 145-151 ◽  
Author(s):  
N. Obradovic ◽  
S. Filipovic ◽  
V.B. Pavlovic ◽  
A. Maricic ◽  
N. Mitrovic ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Activation ◽  
Ball Mill ◽  
Sintering Process ◽  
Zinc Titanate ◽  
Magnesium Titanate ◽  
Titanate Ceramics ◽  
Scanning Electron

In this article the influence of mechanical activation on sintering process of magnesium-titanate and barium-zinc-titanate ceramics has been investigated. Both nonactivated and mixtures treated in planetary ball mill for 80 minutes were sintered at 1100?C and 1300?C. The influence of mechanical activation on phase composition and crystal structure has been analyzed by XRD, while the effect of activation and sintering process on microstructure was investigated by scanning electron microscopy. It has been established that temperature of 1100?C was to low to induce final sintering stage for both systems. Moreover, we concluded that barium-zinc-titanate ceramics exhibited better sinterability than magnesium-titanate ceramics.

Structural Systematics of Rare Earth Complexes. VII. Crystal Structure of Bis(2,2'/6',2␛-Terpyridinium) Octaaquaterbium(III) Heptachloride Hydrate

1994 ◽  
Vol 47 (2) ◽  
pp. 391 ◽  
Author(s):  
CJ Kepert ◽  
BW Skeleton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystal ◽  
Structural Characterization ◽  
Title Compound ◽  
Room Temperature ◽  
Chloride Ions ◽  
Full Matrix ◽  
X Ray

The room-temperature single-crystal X-ray structural characterization of the title compound (tpyH2)2[Tb(OH2)8]Cl7.~2⅓H2O is recorded. Crystals are triclinic, Pī , a 17.063(5), b 16.243(3), c 7.878(3) Ǻ, α 84.78(2), β 84.39(3), γ 87.81(2)°, Z = 2 formula units; 3167 'observed' diffractometer reflections were refined by full-matrix least-squares procedures to a residual of 0.057. Notable features of interest of the compound are the 'chelation' of chloride ions by the terpyridinium cations , and the existence of a free [Tb(OH2)8]2+ cation in the presence of an abundance of chloride ions.

scholarly journals The influence of mechanical activation on sintering process of BaCO3-SrCO3-TiO2 system

2012 ◽  
Vol 44 (3) ◽  
pp. 271-280 ◽  
Author(s):  
Darko Kosanovic ◽  
N. Obradovic ◽  
J. Zivojinovic ◽  
A. Maricic ◽  
V.P. Pavlovic ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Activation ◽  
Ball Mill ◽  
Sintering Process ◽  
Electrical Measurements ◽  
Air Atmosphere ◽  
Titanate Ceramics ◽  
Scanning Electron

In this article the influence of mechanical activation on sintering process of bariumstrontium-titanate ceramics has been investigated. Both non-activated and mixtures treated in a planetary ball mill for 5, 10, 20, 40, 80 and 120 minutes were sintered at 1100-1400?C for 2 hours in presence of air atmosphere. The influence of mechanical activation on phase composition and crystal structure has been analyzed by XRD, while the effect of activation and sintering process on microstructure was investigated by scanning electron microscopy. It has been established that temperature of 1100?C was too low to induce final sintering stage for this system. Electrical measurements have been conducted for the densest ceramics sintered at 1400?C for 2 hours.

Synthesis and structural characterization of BaV4O9

2007 ◽  
Vol 63 (2) ◽  
pp. 270-276 ◽  
Author(s):  
Thomas Reeswinkel ◽  
Sebastian Prinz ◽  
Karine M. Sparta ◽  
Georg Roth
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Structural Characterization ◽  
Room Temperature ◽  
Monoclinic Space Group ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Tensor

The new spin ½ V4+ barium oxovanadate BaV4O9 was synthesized and studied by means of single-crystal X-ray diffraction. Its room-temperature structure is monoclinic, space group P2/c. We discuss the temperature evolution of the crystal structure and thermal expansion tensor of the material between 293 and 100 K.

Room temperature ferromagnetism and structural characterization of Fe,Ni co-doped ZnO nanocrystals

2013 ◽  
Vol 287 ◽  
pp. 287-292 ◽  
Author(s):  
Pooja Dhiman ◽  
Khalid Mujasam Batoo ◽  
R.K. Kotnala ◽  
Jagdish Chand ◽  
M. Singh
Keyword(s):  
Structural Characterization ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Zno Nanocrystals ◽  
Doped Zno ◽  
Co Doped

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LVII. Crystal-Structure of Bis(2,6-diacetyl-pyridine)silver(I) Perchlorate

1989 ◽  
Vol 42 (8) ◽  
pp. 1381 ◽  
Author(s):  
SB Silong ◽  
LM Engelhardt ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Structural Characterization ◽  
Room Temperature ◽  
Bond Angle ◽  
Lewis Base ◽  
The Other ◽  
Tridentate Ligands ◽  
Coordination Spheres ◽  
Silver Atoms

The synthesis and room temperature structural characterization of the title compound [AgL2]+(C104)-, L= 2,6-diacetylpyridine, are reported. Crystals are orthorhombic, Pcan, a 19.629(7), b 14.603(4) and c 14.469(4) � , Z = 8; R was 0.050 for 1987 'observed' reflections. The structure contains two independent [AgL2]+ species, the central nitrogen atoms of the quasi-tridentate ligands being opposed in the coordination spheres of the silver atoms. Both have crystallographically imposed 2 symmetry; in one, this is normal to the N-Ag-N line [actual bond angle, 175.6(2); Ag-N, 2.316(6), Ag-O, 2.589(7) and 2.522(7) � ], relating the two ligands. In the other, it is coincident; for one ligand Ag-N and Ag-O are 2.285(8) and 2.500(8) � , while for the other the two values are 2.271(8) and 2.543(7) �. The silver-nitrogen distances are appreciably longer than the value of 2.166(4) � found for the [Ag( py )2]+ cation.

Wear Behavior and Structural Characterization of a Nitrogen Implanted Ti6Al4V Alloy at Different Temperatures

1983 ◽  
Vol 27 ◽  
Author(s):  
R. Martinella ◽  
G. Chevallard ◽  
C. Tosello
Keyword(s):  
Wear Resistance ◽  
Structural Characterization ◽  
Wear Behavior ◽  
Hardened Layer ◽  
Structural Modifications ◽  
Theory Comparison ◽  
Different Temperatures ◽  
Nitrogen Ions ◽  
Wear Tests

ABSTRACTMechanically polished Ti6Al4V samples were implanted with 100 key nitrogen ions to a fluence of 5.1017 ions/cm2 at two different bulk tenneratures: 370°C and 470°C. Wear tests were carried out with a reciprocating slidina tribotester. Structural modifications and wear morphologies were studied by TEM and SEM. 370°C implanted sample showed the same wear behavior as unimplanted ones, while 470°C implanted sample showed better wear resistance because of a TiN hardened layer. Correlations- between microstructural modifications, wear behavior and mechanisms are reported: results agree with the delamination theory. Comparison with ion- and gas-nitrided samples are presented.

scholarly journals KCTD proteins as Cullin3 E3 Ligase adapters

2014 ◽  
Vol 70 (a1) ◽  
pp. C305-C305
Author(s):  
Alan Ji ◽  
Gilbert Privé
Keyword(s):  
Crystal Structure ◽  
Structural Characterization ◽  
Dissociation Constants ◽  
E3 Ligase ◽  
Terminal Region ◽  
Btb Domain ◽  
Substrate Protein ◽  
Ubiquitin E3 Ligase ◽  
Ubiquitin Moiety

Cullin3 (Cul3) is an ubiquitin E3 ligase responsible for catalyzing the transfer of an ubiquitin moiety from an E2 enzyme to a target substrate protein. The C-terminal region of Cul3 binds RBX1/E2-ubiquitin, while, the N-terminal region interacts with various BTB domain proteins which serve as substrate adaptors. Previously, our group determined the crystal structures of the homodimeric BTB proteins SPOP and KLHL3 in complex with the N-terminal domain of Cul3, revealing the determinants responsible for the BTB/Cul3 interaction [1, 2]. A second class of BTB-domain containing proteins, the KCTD proteins, are also Cul3 substrate adaptors but these do not share many of the previously determined features for Cul3 binding. Furthermore, KCTD proteins form homotetramers and homopentamers via BTB oligomerization rather than the previously described homodimers. Despite these differences, many KCTD proteins interact with Cul3 with dissociation constants of approximately 50 nM. While the target substrates for many of the KCTD/Cul3 E3 ligase complexes are unknown, recent studies have implicated the GABAβ2 receptor as an interactor of KCTD 8, 12, 12b and 16. Here, we report the pentameric crystal structure of the KCTD9 BTB domain and our progress on the structural characterization of Cul3/KCTD/substrate complexes.

Optical, electrical and structural characterization of chloride-doped ZnO nanopillars obtained by electrodeposition

2016 ◽  
Vol 49 (21) ◽  
pp. 215103 ◽  
Author(s):  
M Berruet ◽  
D L Gau ◽  
E A Dalchiele ◽  
M Vázquez ◽  
R E Marotti
Keyword(s):  
Structural Characterization ◽  
Doped Zno
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