Development of a diffusion-controlled solid-state reaction from an initial nucleus

1996 ◽  
Vol 32 (4) ◽  
pp. 420-423 ◽  
Author(s):  
A. G. Knyazeva
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Diffusion Controlled ◽  
Initial Nucleus

scholarly journals Diffusion-Controlled Solid-State Formation of CoSb Phase from Co/Sb-Multilayered Nanowires

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Seong Gi Jeon ◽  
Ho Sun Shin ◽  
Jin Yu ◽  
Jae Yong Song
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Volume Ratio ◽  
Nanometer Scale ◽  
Anodic Aluminum ◽  
Diffusion Controlled ◽  
Properties Of Materials ◽  
Anodic Aluminum Oxide Templates ◽  
Multilayered Nanowires ◽  
Kinetics Of

The physical properties of materials on a nanometer scale are known to be different from those of bulk form due to dimensional confinement effects and high specific surface-to-volume ratio. In this study, the size effects on the diffusion and reaction at the interface of dissimilar nanowires (NWs) were investigated. Co/Sb-multilayered NWs of15±1and19±2 nm in radius have been grown within anodic aluminum oxide templates using a pulsed potentiodynamic electrodeposition method. XRD and TEM results demonstrated that the multilayered NWs were transformed to a CoSb phase through a solid-state reaction at the temperature in the range of 653 to 693 K. The kinetics of the solid-state reaction was analyzed and found to be diffusion controlled at the interface between Co and Sb phases. The reaction was controlled by the dominant diffusion of Sb atoms. The activation energies for the solid-state reaction were estimated to be 0.9 and 0.7 eV/atom for the multilayered NWs with radii of 15 and 19 nm, respectively.

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

Observation of solid-state reaction between a thin yttria film and a (0001) α-alumina substrate

1994 ◽  
Vol 52 ◽  
pp. 644-645
Author(s):  
J. R. Heffelfinger ◽  
C. B. Carter
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Yttrium Aluminum Garnet ◽  
Secondary Phase ◽  
Ceramic Composites ◽  
Alumina Substrate ◽  
Transmission Electron ◽  
Alumina Fibers ◽  
Optical Applications

Transmission-electron microscopy (TEM), scanning-electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were used to investigate the solid-state reaction between a thin yttria film and a (0001) α-alumina substrate. Systems containing Y2O3 (yttria) and Al2O3 (alumina) are seen in many technologically relevant applications. For example, yttria is being explored as a coating material for alumina fibers for metal-ceramic composites. The coating serves as a diffusion barrier and protects the alumina fiber from reacting with the metal matrix. With sufficient time and temperature, yttria in contact with alumina will react to form one or a combination of phases shown by the phase diagram in Figure l. Of the reaction phases, yttrium aluminum garnet (YAG) is used as a material for lasers and other optical applications. In a different application, YAG is formed as a secondary phase in the sintering of AIN. Yttria is added to AIN as a sintering aid and acts as an oxygen getter by reacting with the alumina in AIN to form YAG.

PREDICTION OF GLASS FORMATION BY SOLID STATE REACTION IN ALLOYS

1990 ◽  
Vol 51 (C4) ◽  
pp. C4-111-C4-117 ◽  
Author(s):  
L. J. GALLEGO ◽  
J. A. SOMOZA ◽  
H. M. FERNANDEZ ◽  
J. A. ALONSO
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Glass Formation

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

Electrical assessment of brownmillerite-type calcium ferrite materials obtained by proteic sol-gel route and by solid-state reaction using mollusk shells

2021 ◽  
pp. 122172
Author(s):  
Chrystian G.M. Lima ◽  
Allan J.M. Araújo ◽  
Rinaldo M. Silva ◽  
Rafael A. Raimundo ◽  
João P.F. Grilo ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Sol Gel ◽  
Calcium Ferrite ◽  
Mollusk Shells
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