scholarly journals Solid State Reaction of Al and Zr in Al/Zr Multilayers: A Calorimetry Study

1995 ◽  
Vol 382 ◽  
Author(s):  
K.J. Blobaum ◽  
T.P. Weihs ◽  
T.W. Barbee ◽  
M.A. Wall
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Diffusion Constant ◽  
Nominal Composition ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Two Phases ◽  
Sputter Deposited ◽  
Multi Phase

ABSTRACTThe exothermic, solid state reaction of Al and Zr has been studied in thick AL/Zr multilayers using Differential Scanning Calorimetry and X-ray diffraction. The multilayersamples were magnetron sputter deposited into highly textured alternate layers of Al and Zr with nominal composition A13Zr. The samples used in this study were 47μm thick with a 427Å period. When samples were isochronally scanned from 25º to 725ºC, a large exotherm at ˜350ºC was followed by one or two smaller exotherms at ˜650ºC. The first exotherm is dominated by a diffusionbased reaction of Al and Zr that produces two phases in isochronal scans: amorphous AI-Zrand cubic A13Zr, and two additional phases in isothermal anneals: A12Zr and tetragonal AI3Zr. The exothermic heat from this multi-phase reaction is measured using isochronal scans and isothermal anneals, and the heat flow is analyzed using a l-D diffusion based model. An average activation energy and a diffusion constant are determined. In the isothermal scans, the total exothermic heat increases linearly with √ime, and layer thicknesses vary linearly with heat.

scholarly journals Measuring Enthalpies of Formation Using Thick Multilayer Foils and Differential Scanning Calorimetry

1995 ◽  
Vol 382 ◽  
Author(s):  
T.P. Weihs ◽  
T.W. Barbee ◽  
M.A. Wall
Keyword(s):  
Differential Scanning Calorimetry ◽  
Diffusion Constant ◽  
Enthalpies Of Formation ◽  
Nominal Composition ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Two Phases ◽  
Sputter Deposited ◽  
Multi Phase

ABSTRACTThe exothermic, solid state reaction of Al and Zr has been studied in thick AL/Zr multilayers using Differential Scanning Calorimetry and X-ray diffraction. The multilayersamples were magnetron sputter deposited into highly textured alternate layers of Al and Zr with nominal composition A13Zr. The samples used in this study were 47μm thick with a 427Å period. When samples were isochronally scanned from 25º to 725ºC, a large exotherm at ˜350ºC was followed by one or two smaller exotherms at ˜650ºC. The first exotherm is dominated by a diffusionbased reaction of Al and Zr that produces two phases in isochronal scans: amorphous AI-Zrand cubic A13Zr, and two additional phases in isothermal anneals: A12Zr and tetragonal AI3Zr. The exothermic heat from this multi-phase reaction is measured using isochronal scans and isothermal anneals, and the heat flow is analyzed using a l-D diffusion based model. An average activation energy and a diffusion constant are determined. In the isothermal scans, the total exothermic heat increases linearly with √ime, and layer thicknesses vary linearly with heat.

Fabrication of Lithium Silicate Doped with Lithium Titanate by Solid-State Reaction and its XRD Study

2012 ◽  
Vol 624 ◽  
pp. 200-203
Author(s):  
Yu Tian Wang ◽  
You Dong Cao ◽  
Jin Hu ◽  
Wei Jun Zhang ◽  
Da Ping Wu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Solid Phase ◽  
Raw Materials ◽  
Xrd Analysis ◽  
Lithium Titanate ◽  
Lithium Silicate ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Scanning Calorimetry

Fabrication of lithium silicate powder containing lithium titanate by solid phase reaction method. LiFabrication of lithium silicate powder doped with lithium titanate by solid-state reaction. Take lithium carbonate, silicon dioxide and titania as raw materials and then these powders were mixed according to the different ratios and grinded in an agate mortar for 15 min. And then the mixture were dried at 80°C. Finally, the samples were sintered in vacuum tube furnace at 750, 800, 850 and 900°C for 2h. Thermogravimetric analysis, differential scanning calorimetry and XRD analysis were carried out systematically in this paper. The reaction process and mechanism at different temperatures and the effect of the different ratios and sintering temperature were discussed. Experimental results showed that lithium titanate component increased with increasing amount of titanium dioxide. While the mixture were sintered at 900°C for 2h, there would have lithium silicate and lithium titanate phase.

SYNTHESIS, MAGNETIC AND TRANSPORT PROPERTIES OF Ru1-xSbxSr2GdCu2O8 COMPOUNDS

2004 ◽  
Vol 18 (15) ◽  
pp. 2177-2183 ◽  
Author(s):  
G. ILONCA ◽  
S. PATAPIS ◽  
E. MACOCIAN ◽  
F. BEIUSAN ◽  
T. JURCUT ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Solid State ◽  
Transport Properties ◽  
Solid State Reaction ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Transport Measurements ◽  
Sb Doping

Polycrystalline samples with a nominal composition Ru 1-x Sb x Sr 2 GdCu 2 O 8-d were prepared by a solid state reaction technique. A mixture of RuO 2, Sb 2 O 3, Gd 2 O 3, SrCO 3 and CuO was used to obtain the samples. We performed X-ray diffraction analyses, DC susceptibility and transport measurements and the studies showed that the samples were almost pure Ru -1212 phase. We also observed that Sb doping reduce the conductivity of the system and the transition temperature decreases with increasing Sb content. This may be due to a distortion of RuO 6 octahedral which is responsible for the increase of holes localization.

VARIATION OF Tc IN SINGLE PHASE Bi2Sr2Ca1Cu2O8−x SYSTEM

1991 ◽  
Vol 05 (24n25) ◽  
pp. 1645-1653
Author(s):  
M. NASIR KHAN ◽  
F.A. KHWAJA ◽  
RAANA FARID
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Electron Density ◽  
Solid State Reaction ◽  
Single Phase ◽  
High Temperature Superconductor ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
X Ray

The variation of Tc in a single-phase high temperature superconductor Bi 2 Sr 2 Ca 1 Cu 2 O 8−x is studied using techniques like X-ray diffraction, magnetic and electric measurements. The samples of Bi-Sr-Ca-Cu-O (with nominal composition 2212) are synthesized by solid state reaction using appropriate amounts of Bi 2 O 3, SrCO 3, CaCO 3 and CuO powders. The Tc is found to vary from 92 K to 115 K in the quenched samples. These changes in the value of Tc have been related to the changes in the inter-layer spacing. It is concluded that an increase in the electron density due to shortening of the inter-layer increases the attractive interaction between pairs and is thus responsible for the high Tc in these superconductors.

THE COPPER VALENCE STATE AND THE STRUCTURE OF Li, Ce, Eu, V-DOPED Y-Ba-Cu-O SYSTEM

1989 ◽  
Vol 03 (12) ◽  
pp. 955-960 ◽  
Author(s):  
J.B. ZHANG ◽  
L.F. QU ◽  
K.Y. HOU ◽  
D.L. YANG ◽  
D.J. CHEN ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Diffraction Analysis ◽  
Solid State Reaction ◽  
Valence State ◽  
Nominal Composition ◽  
Iodometric Titration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Valence

High-Tc superconductors with nominal composition of YBa 2 Cu 3 O y and Y 1−x L x Ba 2 Cu 3 O y ( L=Li , Ce, Eu, V) were synthesis by the solid state reaction of appropriate amount of Y 2 O 3, BaO or BaCO 3, Cu 2 O , CuO, and LO x. The Cu 3+/ Cu 2+ ratio was determined by Iodometric titration and oxygen content in the oxides calculated from the ratio. The crystal structure was determined by electron and powder X-ray diffraction analysis. It shows that that ratio of Cu 3+/ Cu 2+ and the crystal structure could be changed as dopping appropriate amount of metal in the Y-Ba-Cu-O system.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

Effect of Sintering Temperature on Electrical Properties of SFN Ceramics Doped with Al Prepared by a Solid-State Reaction Technique

2016 ◽  
Vol 675-676 ◽  
pp. 527-530
Author(s):  
Thanatep Phatungthane ◽  
Kachaporn Sanjoom ◽  
Denis Russell Sweatman ◽  
Buagun Samran ◽  
Chamnan Randorn ◽  
...  
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Solid State Reaction ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Dielectric Behavior ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
Pure Perovskite Phase

In the present work, strontium iron niobate SrFe0.5Nb0.5O3 ceramics doped with aluminum were synthesized by a solid-state reaction technique. Phase formation investigation by X-ray diffraction technique (XRD) revealed that all ceramics exhibited pure perovskite phase with orthorhombic symmetry. Grain size observed by electron microscopy (SEM) was found to increase with increasing sintering temperature. The electrical properties and related parameters of the ceramics were also measured. The ceramics exhibit very good dielectric behavior and have a significant potential for dielectric applications.

Preparation of Ultra–Fine La3NbO7 Powder by Solid State Reaction

2012 ◽  
Vol 512-515 ◽  
pp. 158-161 ◽  
Author(s):  
Ling Dai ◽  
Qiang Xu ◽  
Shi Zhen Zhu ◽  
Ling Liu
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Thermal Barrier ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granular Particle ◽  
Fine Particle Size ◽  
Ultra Fine Particle ◽  
Different Temperatures

As a new candidate material for the ceramic layer in thermal barrier coatings (TBCs) system, La3NbO7 was synthesized with La2O3 powder and Nb2O5 powder by solid state reaction. The stating powders with a mole ratio of La to Nb of 3:1 were mixed and then the mixture was calcined under the different temperatures(800°C, 1000°C, 1200°C) and dwell times(2h, 6h, 10h). The phase structure of the powder was observed by X–ray diffraction(XRD), and the microstructure of the sample was observed by scanning electron microscope(SEM). The effect of calcination temperature and dwell Time on the phase formation were examined. The results indicate that the La3NbO7 powder with single phase can be synthesized successfully at 1200°C for 10h in air, and the La3NbOsub>7 powders synthesized have an ultra-fine particle size of 0.5˜1µm with a granular particle shape. With the temperature increasing, LaNbO4/sub> was synthesized firstly and then La3NbO7 was synthesized with a mole ratio of La2O3 to LaNbO4 of 1:1.

Thermal enhancement of 2H11/2→4I15/2 up-conversion luminescence of Er3+ doped K2Yb(PO4)(MoO4) phosphors

2021 ◽  
Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Reaction Method ◽  
X Ray ◽  
Thermal Enhancement

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...

Changes in Crystallite Size of Tricalcium Silicate during the Laboratory Grinding

2021 ◽  
Vol 321 ◽  
pp. 23-27
Author(s):  
Simona Ravaszová ◽  
Karel Dvořák
Keyword(s):  
Solid State ◽  
Crystallite Size ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Tricalcium Silicate ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Grinding Time

The paper is focused on one of the most important component of Portland clinker-on the tricalcium silicate. The study reported in this article is focuses on the changes in crystallite size of synthetic tricalcium silicate obtained using solid state reaction method. Crystallite size changes are monitored during the grinding in three types of laboratory mills in two different conditions. Changing in crystallite size at various grinding time up to 120 minutes are studied with the aid of X-ray diffraction and using the Scherrer equation. It has been found that the most efficient laboratory mill in terms of speed and fineness of the material was the planetary mill.

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