scholarly journals The Observation of the Reaction Sintering Process of the AlN-Al System, by High Temperature X-ray Diffraction

1967 ◽  
Vol 75 (864) ◽  
pp. 241-246 ◽  
Author(s):  
Sigetomo MATSUO ◽  
Katsutoshi KOMEYA ◽  
Yoshiaki MATSUKI ◽  
Satoshi SHIKANAI
2017 ◽  
Vol 36 (6) ◽  
pp. 635-640
Author(s):  
Esra Öztürk

AbstractThe silicate-type and Eu3+-activated Sr3SiO5 and Mg3SiO5 were prepared through the high temperature solid state reaction method under an open atmosphere. DTA/TG analysis was conducted to obtain information about the thermal behaviors of the mixed reactants. Using the DTA/TG results, the sintering process was achieved and the phase properties were characterized by X-ray diffraction (XRD). The effects of the same activator (Eu3+) and co-dopant (Dy3+) on the photoluminescence (PL) properties of the host lattices were investigated by using a photoluminescence spectrometer.


2016 ◽  
Vol 61 (4) ◽  
pp. 1761-1766
Author(s):  
B. Wodecka-Dus ◽  
M. Adamczyk ◽  
T. Goryczka ◽  
J. Dzik ◽  
D. Radoszewska ◽  
...  

Abstract The present paper widely describes the details of technology of (Ba0.6Pb0.4)TiO3 ceramics modified with PbO-B2O3-Al2O3-WO3 special glass, as well as the influence of admixture on the microstructure and crystal structure of basic material. The microstructure investigations reveal the significant increase of grain size and a decrease of pores participation in volume of modified samples, whereas the X-Ray Diffraction (XRD) measurements show a decrease of the volume of unit cell. The obtained results are discussed due to processes occurring during the sintering process at high temperature.


2015 ◽  
Vol 655 ◽  
pp. 164-167 ◽  
Author(s):  
Xu Sheng Hu ◽  
Guo Guang Yao ◽  
Xiu Lao Tian

Li2ZnTi3O8ceramics were prepared by reaction-sintering process (calcination free). The crystal phase and microstructure were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). A pure phase of Li2ZnTi3O8ceramics sintered at 1075 °C-1150 °C with cubic spinel structure was confirmed by XRD. The microwave dielectric properties (εr,Qxf) of Li2ZnTi3O8ceramics were strongly dependent on the densification and grain size. The τfof Li2ZnTi3O8ceramics was almost independent with the sintering temperatures. In particular, Li2ZnTi3O8ceramics by reaction-sintering method sintered at 1125 °C for 5 h exhibited good combination microwave dielectric properties of εr=21.7, Q×f=70 500 GHz (at 7.5 GHz) and τf=-13 ppm/°C.


2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 369-374 ◽  
Author(s):  
D. Garipoli ◽  
P. Bergese ◽  
E. Bontempi ◽  
M. Minicucci ◽  
A. Di Cicco ◽  
...  

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.


1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.


1988 ◽  
Vol 133 ◽  
Author(s):  
K. S. Kumar ◽  
S. K. Mannan

ABSTRACTThe mechanical alloying behavior of elemental powders in the Nb-Si, Ta-Si, and Nb-Ta-Si systems was examined via X-ray diffraction. The line compounds NbSi2 and TaSi2 form as crystalline compounds rather than amorphous products, but Nb5Si3 and Ta5Si3, although chemically analogous, respond very differently to mechanical milling. The Ta5Si3 composition goes directly from elemental powders to an amorphous product, whereas Nb5Si3 forms as a crystalline compound. The Nb5Si3 compound consists of both the tetragonal room-temperature α phase (c/a = 1.8) and the tetragonal high-temperature β phase (c/a = 0.5). Substituting increasing amounts of Ta for Nb in Nb5Si3 initially stabilizes the α-Nb5Si3 structure preferentially, and subsequently inhibits the formation of a crystalline compound.


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