Titanium disilicide

Borides, Silicides, III—VandII—VI Compounds 331 2.7 Titanium Disilicide... 

Titanium disilicide (TiSi2) has very low electrical resistivity and is a promising metallization material.P ] It is deposited by the following reaction ... 

Ti(H2P04,)3 has been prepared by treating titanium disilicide, TiSi2, with H 3 PO4. The reaction of diethyl chlorophosphate, (EtO)2 P(0)C1, with anhyd rous TiCl3 at elevated temperatures leads to de-ethylation of the phosphate and the precipitation of Ti(ethoxychlorophosphate)3. ... 

Titanium disilicide [12039-83-7] is a silvery-gray, crystalline material that oxidizes slowly in air when heated to 700—800°C. It is resistant both to mineral acids (except hydrofluoric) and to aqueous solutions of alkalies, but reacts with fused borax, sodium hydroxide, and potassium hydroxide. It reacts explosively with chlorine at high temperatures. 

The deposition processes discussed so far typically operate such that all the material required for the growing film comes from the overlying gas or liquid phase. Other deposition reactions involve reaction (and therefore consumption) of the underlying substrate itself. Examples of such deposition processes include thermal oxidation, nitridation, or silicidation of silicon, which can be accomplished by exposing a silicon wafer at high temperature to oxygen, ammonia, or titanium tetrachloride, respectively, to form silicon dioxide, silicon nitride, or titanium disilicide. Solid-phase diffusion and reaction processes are involved in each case. 

E. Ludenscheider, U. Westermann, J. Wonka, H. Meinhardt, H. Neisius, R. Arnold Investigations on Molybdenum and Titanium Disilicide as Structural Materials for Highest Temperatures. In O. Izumi (ed.) Proc. Int. Symp. Intermetallic Compounds - Structure and Mechanical Properties (JIMIS-6).The Japan Institute of Metals, Sendai (1991)621-625. 

Titanium silicon carbide MAX phase was synthesized by pressureless sintering of ball milled TiC and Si powders of six different compositions. The sintering reactions were evaluated in situ by dilatometer analysis under flowing argon gas. The as-sintered samples were evaluated using mainly x-ray diffraction (XRD) analysis. This study showed that titanium carbide, silicon carbide and titanium disilicide were present as intermediate or secondary phases in the samples. 

Figure 3 shows x-ray diffractograms of the samples sintered under vacuum for 2 hours and 30 min in 1250 C. The B sample with the lowest amount of silicon in the starting powder differs from the other samples. It is the only sample which does not contain silicon carbide (SiC) and titanium disilicide (TiSi2). All samples contained titanium silicon carbide MAX phase (TisSiCj) and titanium carbide (TiC). 

Raju, G. B., Basu, B. (2007). Densifica-tion. Sintering Reactions, and Properties of Titanium Diboride With Titanium Disilicide as a Sintering Aid. J. Am. Ceram. Soc., 90, 3415.3423. 

The silicides of major industrial importance are the disilicides of the refractory metals molybdenum, tantalum, titanium, tungsten, vanadium, and zirconium.pl] These compounds are of great interest par-... 

Nickel aluminide (NiAl, Ni3AI), titanium aluminide (TiAl, Ti3AI), molybdenum disilicide (MoSi2)... 

Intermet allies Nickel aluminide (NiAl, NijAl) Titanium aluminide (TiAl, TijAl) Molybdenum disilicide (MoSi )... 

SAFETY PROFILE A highly corrosive irritant to the eyes, skin, and mucous membranes. Mildly toxic by inhalation, Explosive reaction with alcohols + hydrogen cyanide, potassium permanganate, sodium (with aqueous HCl), tetraselenium tetranitride. Ignition on contact with aluminum-titanium alloys (with HCl vapor), fluorine, hexa-lithium disilicide, metal acetylides or carbides (e.g., cesium acetylide, rubidium ace-tylide). Violent reaction with 1,1-difluoro-ethylene. Vigorous reaction with aluminum, chlorine + dinitroanilines (evolves gas). Potentially dangerous reaction with sulfuric acid releases HCl gas. Adsorption of the acid onto silicon dioxide is exothermic. See also HYDROGEN CHLORIDE (AEROSOL) and HYDROCHLORIC ACID. 

The temperature dependence of the linear thermal expansion coefficients a(T) of the investigated titanium silicides are illustrated in fig. 6. The complex hexagonal Ti5Si3 compound exhibits a (T) values lower than those of the disilicide TiSi2 with the closer packed C54 structure. Another reason is that the anharmonicity of the lattice vibrations -phonons- and the asymmetry of the lattice potential curves of the Ti-Si and Si-Si bonds of the C54 structure are more pronounced compared to that of the D8S lattice. 

ACIDE CHLORHYDRIQUE (French) (7647-01-0) Hydrogen chloride gas is quickly absorbed in water, forming hydrochloric acid. Hydrochloric acid is a strong acid. Violent reaction with bases, strong oxidizers (with release of chlorine gas), acetic anhydride, cesium cyanotridecahydrodecaborate(2-), ethylidine difluoride, hexalithium disilicide, metal acetylides. sodium, silicon dioxide, tetraselenium tetranitride, and many organic materials. Incompatible with aliphatic amines, alkanolamines, alkylene oxides, aluminum, aluminum-titanium alloys, aromatic amines, amides, 2-aminoethanol, ammonia, ammonium hydroxide, calcium phosphide, chlorosulfonic acid, ethylene diamine, ethyleneimine, epichlorohydrin, isocyanates, metal acetylides, metal carbides, oleum, organic anhydrides, perchloric acid,... 

B4C), nitrides such as silicon nitride (Si3N4) and boron nitride (BN), borides such titanium diboride (TiB2), silicides such as molybdenum disilicide (MoSi2) and halides such as lithium fluoride (LiF). There are also compounds based on nitride-oxide or oxynitride systems (e.g., p -sialons with the general formula Sie-jAl Ng-jOj., whCTe 0 < z < 4). 

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