Силицид меди (Cu5Si)

Description

Copper silicide Cu5Si is an intermetallic compound of copper and silicon, a product of the interaction of copper with silicon in the solid phase. Belongs to the class of metallic transition metal silicides, combining metallic electrical conductivity with increased hardness and chemical resistance compared to pure copper. In the Cu–Si system, this is one of the intermediate phases along with other copper silicides of various stoichiometries.

Basic Attributes

• CAS No: 12159-07-8
• Chemical formula: Cu5Si (elemental composition of Cu, Si)
• English name: Copper silicide (Cu5Si)
• Molecular Weight: 345.82
• Exact weight: 342.62500
• EU number: 235-286-8
• XLogP3: -0.39330
• Synonyms and related CAS: 1234633-48-7, 1301726-73-7

Physico-chemical characteristics

• Appearance: silvery flakes/plates with a metallic sheen (source: “silver coins”, an artifact of machine translation of the English description of the powder)
• Density: 7.7–7.8 g/cm³
• Melting point: 825 °C
• Solubility in water: insoluble
• Steam pressure: 54300 mm Hg. Art. at 25 °C (the value from the supplier’s data sheet is physically abnormally high for a refractory intermetallic compound and probably relates to an error in the conversion of units in the source; given as is)

Substance class and structure

Cu5Si is a metal-like silicide with a predominance of copper in the crystal lattice; silicon occupies part of the lattice nodes, distorting it and increasing hardness and oxidation resistance compared to pure copper. Retains the high electrical and thermal conductivity characteristic of copper, with increased corrosion resistance and wear resistance.

Scope of application

In electronics and semiconductor manufacturing, it is used as a diffusion barrier and contact material in thin-film structures, preventing mutual diffusion of copper and silicon at the layer boundaries. In the form of targets, it is used for magnetron sputtering (sputtering target) when depositing thin films in microelectronics. In metallurgy, copper alloys are introduced as an alloying component that increases mechanical characteristics and resistance to oxidation under harsh operating conditions. Used in coatings and surface treatments to provide resistance to oxidation at elevated temperatures.

Storage and transportation

Store in an airtight container, in a dry place, away from sources of moisture and strong oxidizing agents. Special UN transport codes and hazard classes are not indicated in the passport data; When working with powder/flakes, observe general dust protection measures - gloves, safety glasses, and in case of significant dust - a respirator.

Additional technical information

The combination of high density (7.7–7.8 g/cm³, which is noticeably higher than the density of pure silicon and lower than the density of pure copper) and a high melting point of 825 ° C is typical for transition metal intermetallic compounds with silicon: the copper lattice is compacted by embedded silicon atoms, which increases the hardness and temperature resistance of the material compared to pure copper, which has a melting point of 1085 ° C, but which noticeably softer in contact structures. Insolubility in water ensures the chemical stability of the material when stored in air under normal humidity conditions; the substance does not hydrolyze and does not form soluble compounds upon contact with atmospheric moisture.

Delivery form

Supplied in the form of powder or small flakes/plates, as well as in the form of sintered targets of a given purity and geometry for vacuum deposition equipment. The purity and particle size distribution are selected for a specific technological task - from alloying additives in metallurgy to precision targets for thin-film processes in microelectronics.