Joining ductile refractory metal inserts in x-ray tube targets

ABSTRACTRefractory metal suicides have been used widely in VLSI fabrication, owing to their low resistivity, high-temperature compatibility, and oxidiz-ability. In this work, we have studied the titanium suicide formation, using a rapid thermal processor (RTP). Isothermal and isochronal sintering experiments were carried out to determine the appropriate process steps. The selective etch of the unreacted Ti was characterized. The sintered films were characterized by four-point probe, X-ray diffraction, and Auger electron spectroscopy. We also studied the oxidation at 800–1000°C of Ti suicide formed by sintering Ti and polycrystalline silicon using a RTP in N2 ambient. The oxidation results of Ti suicide formed using RTP in N2 ambient are compared with those formed using furnace sintering in vacuum/argon ambient and those deposited by cosputtering.

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Development of Nanocrystalline Copper-Refractory Metal Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.2373 ◽

2007 ◽

Vol 561-565 ◽

pp. 2373-2378 ◽

Cited By ~ 5

Author(s):

J.M. Rigsbee

Keyword(s):

Electron Microscopy ◽

Vapor Deposition ◽

Refractory Metal ◽

Physical Vapor Deposition ◽

Strength Loss ◽

Strength Properties ◽

Metal Alloys ◽

X Ray ◽

Precipitate Coarsening ◽

Refractory Metal Alloys

Precipitation-strengthened Cu-based alloys have limited use as structural materials at high temperatures due to precipitate coarsening and strength loss. We have recently shown that Curefractory metal alloys produced by various physical vapor deposition methods have stable, nanocrystalline microstructures and maintain their strength properties even when annealed at temperatures as high as 900 C for up to 100 hours. This paper presents discussions of how these alloys are processed and the resulting microstructures. X-ray and electron microscopy results will be presented to document the phase transformations that occur in these alloys and result in such exceptionally stable microstructures.

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Study of Wsi2 and Cosi2 Thin Films Deposited by Laser Ablation

MRS Proceedings ◽

10.1557/proc-354-659 ◽

1994 ◽

Vol 354 ◽

Author(s):

V.G. Glebovsky ◽

S.N. Ermolov ◽

R.A. Oganyan ◽

E.D. Stinov

Keyword(s):

Thin Films ◽

Laser Ablation ◽

Elemental Composition ◽

Refractory Metal ◽

Liquid State ◽

Electric Resistance ◽

Cobalt Disilicide ◽

X Ray ◽

Specific Electric Resistance

AbstractIt has been shown, that pure massive targets of tungsten and cobalt disilicide can be obtain from the liquid state by means of a set of metallurgical methods. The conditions of laser ablation of the targets ensuring the preparation of tungsten and cobalt suicide films of the specific electric resistance 50 and 30 μΩ cm respectivly have been studied. The grazing beam X-ray difractometry were used to investigate their phase and elemental composition of the films. The method in question has been shown to be promising for the preparation of films of other refractory - metal suicides.

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PHASE EQUILIBRIA IN THE NaCl–CaCl2–CaO SYSTEM

Ukrainian Chemistry Journal ◽

10.33609/2708-129x.87.02.2021.77-86 ◽

2021 ◽

Vol 87 (2) ◽

pp. 77-86

Author(s):

Anatoliy Omelchuk ◽

Igor Skryptun ◽

Nikolay Zakharchenko ◽

Olha Bosenko ◽

Ruslan Savchuk ◽

...

Keyword(s):

Ternary System ◽

Phase Equilibria ◽

Metal Oxides ◽

Calcium Oxide ◽

Refractory Metal ◽

Polythermal Section ◽

X Ray ◽

Polythermal Sections ◽

Solid Phases ◽

Liquid And Solid Phases

The phase equilibria of the ternary system CaCl2 – NaCl – CaO in the area which enriched of calcium and sodium chloride were investigated by the methods of differential-thermal analysis and powder X-ray phase analysis. In the systems were determined the equilibrium concentration of calcium oxide and the composition of the phases, which at the same time exist in an equilibrium state at different temperatures. The surfaces of liquidus and solidus were established, the compositions of the sections of the ternary system CaCl2–NaCl–CaO were defined, which recommended for electrochemical reduction of refractory metal oxides (titanium, zirconium and other), which allow electrolysis in the temperature range from 550 to 1000 °С. Five polythermal sections of the NaCl – CaCl2 – CaO ternary system were studied. For each polythermal section the regions of existence of the liquid and solid phases were established. For each polythermal section state diagrams were constructed. Used X-Ray phase analyses it was established the compositions of liquid and solid phases for each polythermal sections. The phases of which the system consists were determined. At a constant ratio of components [NaCl]:[CaCl2] = 1.06 (mol.) in the melts of the ternary system CaCl2 – NaCl – CaO, the equilibrium content of calcium oxide reaches 12.0 mol.%, while their crystallization temperature does not exceed 550 °C. This allows us to recommend mixtures of this composition for electrochemical reduction of refractory metal oxides in a wide range of temperatures (from 550 to 1000 °C) with a high content of both calcium and sodium chlorides (not less than 40 mol.%) and oxide. calcium (up to 12.0 mol.%). The eutectic of this ternary system has a melting point of 480 ° C and corresponds to he composition (mol.%): CaCl2 (45.8) – NaCl (47.0) – CaO (7.2).

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Refinement of Crystallographic Parameters in Refractory Metal Disilicides

MRS Proceedings ◽

10.1557/proc-646-n4.3.1 ◽

2000 ◽

Vol 646 ◽

Cited By ~ 15

Author(s):

K. Tanaka ◽

K. Nawata ◽

H. Inui ◽

M. Yamaguchi ◽

M. Koiwa

Keyword(s):

Refractory Metal ◽

Interatomic Distance ◽

X Ray Diffraction ◽

Space Group ◽

X Ray ◽

Lattice Constants ◽

Metal Atoms ◽

Crystallographic Structures ◽

Atomic Parameters ◽

The Ideal

ABSTRACTThe crystallographic structures of seven refractory metal (Ti, V, Cr, Nb, Mo, Ta and W) disilicides with the C11b, C40 and C54 structures have been refined through analysis of single-crystal X-ray diffraction data. Crystallographic parameters refined are lattice constants, atomic parameters and the space group of the C40 disilicides. In most of previous studies, silicon atoms have been considered to locate at the ideal positions so that the refractory metal atoms are perfectly six-fold coordinated in RSi2 layers prevailing in all the three structures. The present analysis shows that the silicon atoms are displaced from the ideal positions. The magnitude of such displacement is found to be closely related to the interatomic distance in these pseudo-hexagonally arranged RSi2 layers. The space group of three of the four C40 disilicides, VSi2, CrSi2 and TaSi2, is determined to be P6422, which is of chirality with respect to that (P6222) assigned in the previous studies.

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Refractory Silicide Schottky Contacts To Gaas

MRS Proceedings ◽

10.1557/proc-54-401 ◽

1985 ◽

Vol 54 ◽

Cited By ~ 2

Author(s):

N. Yokoyama ◽

T. Ohnishi ◽

T. Nakamura ◽

H. Nishi

Keyword(s):

High Temperature ◽

Electrical Properties ◽

Refractory Metal ◽

Schottky Contacts ◽

Electrical Characteristics ◽

X Ray

ABSTRACTRefractory suicides form high temperature stable Schottky contacts to GaAs. This finding enabled us to develop self-aligned GaAs MESFETs, thereby enabling the development of today's GaAs ICs. This paper reviews electrical and metallurgical studies on refractory-metal/GaAs and refractory-metal-si licide/GaAs interfaces. We emphasize the fact that W5Si3/GaAs contacts have extremely stable electrical properties even after annealing at temperatures up to 850°C. Crystallographical properties of the W5S3 film on GaAs, investigated by x-ray and TEM measurement techiques, are also covered. We found that the Schottky electrical characteristics are not affected by whether the film is amorphous or crystalline.

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