Chinese Name: Hafnium silicide

English Name: Hafnium silicide

CAS:12401-56-8

EINECS:235-640-1

MDL No.: mfcd00167026

Density (g / ml, 25 ℃): 8.02

Melting point (º C): 1680

Density: 8.02

Melting point: 1680 º C

Molecular formula: h8hfsi2

Molecular weight: 242.72500

Accurate mass: 243.96300

Single isotope mass: 243.962952da

Nominal mass: 244da

Average mass: 242.7245da

Performance characteristics:

Hafnium silicide is a transition metal silicide and a refractory intermetallic compound. Due to its unique physical and chemical properties, it is applied to thin film coatings, block structures, electrothermal elements, thermoelectric materials and photovoltaic materials.

In addition, Hafnium silicide nanomaterials also have special electrical and optical properties, magnetoelectric and thermoelectric properties, and have potential applications in the field of catalysis. Hafnium silicide products are characterized by high purity, small particle size, uniform distribution, large specific surface area and high surface activity.

Hafnium silicide is most commonly used in ceramic materials for manufacturing various high-temperature components and functional components.

Application of Hafnium silicide in material preparation:

1. Silicon carbide Hafnium silicide tantalum silicide (SiC – hfsi2 – TaSi2) ablative composite coating carbon fiber reinforced carbon (C / C) composite is a new kind of high temperature resistant composite material with carbon fiber as reinforcement and pyrolytic carbon as matrix. Because of its excellent high-temperature strength, ablation resistance and good friction and wear performance, the United States carried out the research work of C / C composite materials for thermal structure in the early 1970s, which made C / C composite materials develop from burning heat protection materials to thermal structure materials. As a thermal structural material, C / C composites can be used for gas turbine engine structural components, nose cone cap of space shuttle, wing leading edge, etc. most of these components work under high temperature and oxidation environment. However, C / C composites are easy to oxidize and can not normally be used in oxidation atmosphere above 400 ℃. This requires proper anti-oxidation protection for C / C composites, and the preparation of anti-oxidation coating is one of the main protective measures. The results show that the ablation resistance of C / C composites can be further improved when refractory metals Zr, HF, Ta and TiB2 are added to the carbon matrix. In order to understand the influence of metal HF and TA on the ablation performance of C / C composites, sic-hfsi2-tasi2 anti ablation coating was prepared by embedding method, and the ablation performance of the anti ablation coating was measured by oxyacetylene ablation device. junction

2. Preparing an organic electroluminescent device. Comprising an anode, a light emitting layer, a cathode and a package cover which are sequentially stacked, the package cover encapsulates the light emitting layer and the cathode on the anode, the package cover includes a silicon nitride layer and a barrier layer formed on the surface of the silicon nitride layer; The material of the barrier layer comprises a silicide and a metal oxide, the silicide is selected from at least one of chromium silicide, tantalum disilicide, Hafnium silicide, titanium disilicide, molybdenum disilicide and tungsten disilicide, and the metal oxide is selected from at least one of magnesium oxide, aluminum trioxide, titanium dioxide, zirconium oxide, hafnium dioxide and tantalum pentoxide. The organic electroluminescent device has a long life. The invention also provides a preparation method of an organic electroluminescent device.

3. Preparing a silicon germanium alloy based thermoelectric element. The silicon germanium alloy based thermoelectric element is composed of an electrode layer, a silicon germanium alloy based thermoelectric layer and a barrier layer between the electrode layer and the silicon germanium alloy based thermoelectric layer. The barrier layer is a mixture of silicide and silicon nitride. The silicide is at least one of molybdenum silicide, tungsten silicide, cobalt silicide, nickel silicide, niobium silicide, zirconium silicide, tantalum silicide and Hafnium silicide. The silicon germanium alloy based thermoelectric element provided has good interface bonding, no crack and obvious diffusion phenomenon at the interface, small contact resistance, good thermal contact state, and can withstand long-term high-temperature acceleration test. In addition, the preparation method provided has the characteristics of simple process, high reliability, low cost, no special equipment and suitable for large-scale production.

4. Prepare a high temperature resistant and oxidation resistant cermet composite coating. The composite film is characterized in that the coating is composed of refractory metal, refractory carbide and intermetallic compound, and the coating thickness is 10 μ m~50 μ m。 The refractory metal is one or more of molybdenum, tantalum, zirconium and hafnium; The refractory carbide is composed of silicon carbide and one or more of tantalum carbide, zirconium carbide and hafnium carbide; The intermetallic compound composition is one or more of molybdenum silicide, tantalum silicide, zirconium silicide, Hafnium silicide, tantalum carbon silicide, zirconium carbon silicide and hafnium carbon silicide; The crystal structure of the coating is composed of amorphous and / or polycrystalline nanoparticles.

Storage method:

This product should be sealed and stored in a dry and cool environment. It should not be exposed to the air for a long time to prevent agglomeration due to moisture, which will affect the dispersion performance and use effect. In addition, it should avoid heavy pressure and contact with oxidant. It should be transported as ordinary goods.