A Moessbauer Effect and X-Ray Diffraction Investigation of Ti—Sn Intermetallic Compounds. Part 1. Equilibrium Phases.

ChemInform ◽  
2003 ◽  
Vol 34 (22) ◽  
Author(s):  
J. W. O'Brien ◽  
R. A. Dunlap ◽  
J. R. Dahn
2021 ◽  
Vol 7 (3) ◽  
pp. 42
Author(s):  
Jiba N. Dahal ◽  
Kalangala Sikkanther Syed Ali ◽  
Sanjay R. Mishra

Intermetallic compounds of Dy2Fe16Ga1−xNbx (x = 0.0 to 1.00) were synthesized by arc melting. Samples were investigated for structural, magnetic, and hyperfine properties using X-ray diffraction, vibration sample magnetometer, and Mossbauer spectrometer, respectively. The Rietveld analysis of room temperature X-ray diffraction data shows that all the samples were crystallized in Th2Fe17 structure. The unit cell volume of alloys increased linearly with an increase in Nb content. The maximum Curie temperature Tc ~523 K for x = 0.6 sample is higher than Tc = 153 K of Dy2Fe17. The saturation magnetization decreased linearly with increasing Nb content from 61.57 emu/g for x = 0.0 to 42.46 emu/g for x = 1.0. The Mössbauer spectra and Rietveld analysis showed a small amount of DyFe3 and NbFe2 secondary phases at x = 1.0. The hyperfine field of Dy2Fe16Ga1−xNbx decreased while the isomer shift values increased with the Nb content. The observed increase in isomer shift may have resulted from the decrease in s electron density due to the unit cell volume expansion. The substantial increase in Tc of thus prepared intermetallic compounds is expected to have implications in magnets used for high-temperature applications.


2011 ◽  
Vol 275 ◽  
pp. 251-254
Author(s):  
Hua Wei Rong ◽  
Cheol Hong Park ◽  
Won Jo Park ◽  
Han Ki Yoon

With the rapid development of aerospace and automobile industries, metal matrix composites (MMCs) have attracted much attention because of its excellent performance. In this paper, Ni-Cr/AC8A composites reinforced with porous Ni-Cr preform were manufactured by low pressure infiltration process, infiltration temperatures are 700oC~850oC. The microstructure and phase composition of composites were evaluated using optical microscope, X-ray diffraction (XRD) and electro-probe microanalysis (EPMA), It's found that they're intermetallic compounds generated in the composites. Recently, intermetallic compounds have attracted much attention as high-temperature material. We study the hardness of Ni-Cr/AC8A composites, the results show the Ni-Cr/AC8A composite has high hardness due to the intermetallic compounds exist.


2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940067
Author(s):  
P. Vitiaz ◽  
N. Lyakhov ◽  
T. Grigoreva ◽  
E. Pavlov

The interaction between a solid inert metal Ir and an active liquid metal Ga during mechanical activation in a high-energy planetary mill is studied by X-ray diffraction and scanning electron microscopy with high-resolution energy dispersive X-ray microanalysis. The effect of mechanical activation on the formation of GaxIry intermetallic compounds and GaxIry/Ir composites and their solubility in acids was investigated. The subsequent extraction of Ga from intermetallic compounds and composites in the mixture of concentrated acids [Formula: see text] makes it possible to produce nanoscale Ir.


2007 ◽  
Vol 62 (2) ◽  
pp. 162-168 ◽  
Author(s):  
Selcan Tuncel ◽  
Ute Ch. Rodewald ◽  
Samir F. Matar ◽  
Bernard Chevalier ◽  
Rainer Pöttgena

The magnesium compounds RE4Co2Mg3 (RE = Pr, Gd, Tb, Dy) were prepared by induction melting of the elements in sealed tantalum tubes. The samples were studied by powder X-ray diffraction. The structures of the gadolinium and of the terbium compound were refined from single crystal diffractometer data: Nd4Co2Mg3-type, P2/m, Z = 1, a = 754.0(4), b = 374.1(1), c = 822.5(3) pm, β = 109.65(4)°, wR2 = 0.0649, 730 F2 values for Gd4Co2Mg3 and a = 750.4(2), b = 372.86(6), c = 819.5(2) pm, β = 109.48(3)°, wR2 = 0.0398, 888 F2 values for Tb4Co2Mg3 with 30 variables each. The RE4Co2Mg3 structures are 3 : 1 intergrowth variants of distorted CsCl and AlB2 related slabs of compositions REMg and RECo2. Characteristic structural features (exemplary for Tb4Co2Mg3) are relatively short Tb-Co (271 pm), Co-Co (232 pm) and Mg-Mg (314 pm) distances. The latter are a geometrical constraint of the distortion of the REMg and RECo2 slabs. Chemical bonding analysis (ELF and ECOV data) for Gd4Co2Mg3 reveals strong Gd-Co bonding followed by Mg-Co, while the Mg-Mg interactions can be considered as weak. The Co-Co contacts are only weakly bonding. The bonding and antibonding states are almost filled.


2013 ◽  
Vol 197 ◽  
pp. 137-142 ◽  
Author(s):  
Tomasz Rzychoń ◽  
Janusz Szala ◽  
Tomasz Kukiełka

In this paper the results of microstructural investigations and methodology of detection of intermetallic compounds were reported. The microstructural investigations included the light microscopy, scanning electron microscopy, chemical microanalysis and X-ray diffraction analysis. It was found that the microstructure of Mg-5Al-3Ca-0.7Sr-0.2Mn alloy consists of α-Mg, (Mg,Al)2Ca, Al3Mg13(Sr,Ca), Mg2Ca and Al2Ca intermetallic phases. The correct detection of these phases requires the high magnifications and a large number of measurements fields.


2012 ◽  
Vol 67 (11) ◽  
pp. 1225-1228 ◽  
Author(s):  
Michael Johnscher ◽  
Rainer Pöttgen

The YNi9In2-type copper-rich compounds RECu9Cd2 (RE=La, Ce, Pr, Nd) were synthesized directly from the elements in sealed niobium ampoules in an induction furnace and were characterized by powder X-ray diffraction. The structure of PrCu9Cd2 was refined from single-crystal Xray diffractometer data: P4/mbm, a=849.0(3), c=498.2(3) pm, wR2=0.0418, 374 F2 values, 23 variables. The structure has two striking polyhedral motifs: Pr@Cu16Cd4 and Cu2@Cu8Cd4. The packing of these polyhedra describes the whole structure. The copper and cadmium atoms build up a three-dimensional [Cu9Cd2] network with broader ranges of Cu-Cu (246 - 274 pm) and Cu-Cd (272 - 288 pm) distances. The cadmium atoms show segregation through pair formation with Cd-Cd distances of 288 pm.


2010 ◽  
Vol 25 (11) ◽  
pp. 2175-2182 ◽  
Author(s):  
Alongheng Baated ◽  
Keun-Soo Kim ◽  
Katsuaki Suganuma

The formation of Zn whiskers threatens the reliable operation of electronic equipment with an electrical shorting hazard. As with tin whiskers (much more intensively researched than Zn whiskers), the mechanism of formation is still not clear. This work investigated the Zn whisker growth mechanism for an electroplated Zn coating above a carbon steel substrate from a raised floor tile. Iron–zinc (Fe–Zn) intermetallic and Zn oxides were identified by x-ray diffraction analysis (XRD) and electron probe microanalysis (EPMA). Fe–Zn intermetallic compounds formed on the surface of the Zn layer in addition to the interface between the Zn coating and the steel substrate. Zn oxides formed primarily on the surface of the Zn coating. Fe–Zn intermetallic compounds and Zn oxide formation can be the source of a residual stress that promotes Zn diffusion to the surface of electroplated Zn coating, resulting in the formation of Zn whiskers.


2007 ◽  
Vol 336-338 ◽  
pp. 2340-2343 ◽  
Author(s):  
Song He Meng ◽  
Xing Hong Zhang ◽  
Wei Feng Zhang

The reaction process and kinetics of Al-TiO2-C-Ti-Fe system were investigated by differential scanning calorimetry (DSC) analysis, X-ray diffraction (XRD) analysis and scanning electron microscope (SEM). In order to obtain the information of reaction process for complicated system, the reaction characteristics of Al-TiO2, Al-TiO2-C and Al-TiO2-C-Ti systems are explored firstly. The results show that the reaction process varies with temperature in Al-TiO2-C-Ti-Fe system. At the lower temperature, the dominating reaction in Al-TiO2-C-Ti-Fe system is that between Al and Ti, Al and Fe, and so TiAlx, FeAlx, and Ti2Fe intermetallic compounds form. With the temperature increasing, the intermetallic compounds are decomposed. Then the decomposed Ti and Al react with C and TiO2 respectively and the stable TiC, Al2O3 and Fe three phases form in the final product.


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