| Names | |
|---|---|
| Other names Neptunium disilicide | |
| Identifiers | |
3D model (JSmol) | |
| |
| |
| Properties | |
| NpSi2 | |
| Appearance | Crystals |
| Density | 9.03 |
| insoluble | |
| Related compounds | |
Related compounds | Plutonium silicide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Neptunium silicide is a binary inorganic compound of neptunium and silicon with the chemical formula NpSi
2. [1] The compound forms crystals and does not dissolve in water. [2]
Heating neptunium trifluoride with powdered silicon in vacuum: [3]
Neptunium silicide forms crystals [4] of tetragonal crystal system, space group I41/amd, cell parameters: a = 0.396 nm, c = 1.367 nm, Z = 4. [5]
Neptunium disilicide does not dissolve in water.
Neptunium disilicide reacts with HCl: [3]
A silicide is a type of chemical compound that combines silicon and a usually more electropositive element.
Molybdenum disilicide (MoSi2, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically conductive. At high temperatures it forms a passivation layer of silicon dioxide, protecting it from further oxidation. The thermal stability of MoSi2 alongside its high emissivity make this material, alongside WSi2 attractive for applications as a high emissivity coatings in heat shields for atmospheric entry. MoSi2 is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable. It is insoluble in most acids but soluble in nitric acid and hydrofluoric acid.
Titanium disilicide (TiSi2) is an inorganic chemical compound of titanium and silicon.
Calcium disilicide (CaSi2) is an inorganic compound, a silicide of calcium. It is a whitish or dark grey to black solid matter with melting point 1033 °C. It is insoluble in water, but may decompose when subjected to moisture, evolving hydrogen and producing calcium hydroxide. It decomposes in hot water, and is flammable and may ignite spontaneously in air.
Binary compounds of silicon are binary chemical compounds containing silicon and one other chemical element. Technically the term silicide is reserved for any compounds containing silicon bonded to a more electropositive element. Binary silicon compounds can be grouped into several classes. Saltlike silicides are formed with the electropositive s-block metals. Covalent silicides and silicon compounds occur with hydrogen and the elements in groups 10 to 17.
Polysilicon hydrides are polymers containing only silicon and hydrogen. They have the formula where 0.2 ≤ n ≤ 2.5 and x is the number of monomer units. The polysilicon hydrides are generally colorless or pale-yellow/ocher powders that are easily hydrolyzed and ignite readily in air. The surfaces of silicon prepared by MOCVD using silane (SiH4) consist of a polysilicon hydride.
Yttrium oxyfluoride is an inorganic chemical compound with the formula YOF. Under normal conditions, the compound is a colorless solid.
Nickel silicides include several intermetallic compounds of nickel and silicon. Nickel silicides are important in microelectronics as they form at junctions of nickel and silicon. Additionally thin layers of nickel silicides may have application in imparting surface resistance to nickel alloys.
Iron disilicide (FeSi2) is an intermetallic compound, a silicide of iron that occurs in nature as the rare mineral linzhiite. At room temperature it forms orthorhombic crystals (β phase), which convert into a tetragonal α phase upon heating to 970 °C.
Manganese disilicide (MnSi2) is an intermetallic compound, a silicide of manganese. It is a non-stoichiometric compound, with a silicon deficiency expressed as MnSi2–x. Crystal structures of many MnSi2–x compounds resemble a chimney ladder and are called Nowotny phases. They include MnSi2 (x=0), Mn4Si7 (x=0.250), Mn11Si19 (x=0.273), Mn15Si26 (x=0.267) and Mn27Si47 (x=0.259). These phases have very similar unit cells whose length varies from 1.75 nm for MnSi2 or Mn4Si7, which have almost the same structures, to 11.8 nm for Mn27Si47.
Nickel monosilicide is an intermetallic compound formed out of nickel and silicon. Like other nickel silicides, NiSi is of importance in the area of microelectronics.
Praseodymium(IV) fluoride (also praseodymium tetrafluoride) is a binary inorganic compound, a highly oxidised metal salt of praseodymium and fluoride with the chemical formula PrF4.
Neptunium (IV) oxalate is an inorganic compound, a salt of neptunium and oxalic acid with the chemical formula Np(C2O4)2. The compound is slightly soluble in water, forms crystalline hydrates—green crystals.
Neptunium arsenide is a binary inorganic compound of neptunium and arsenic with the chemical formula NpAs. The compound forms crystals.
Neptunium diarsenide is a binary inorganic compound of neptunium and arsenic with the chemical formula NpAs
2. The compound forms crystals.
Plutonium silicide is a binary inorganic compound of plutonium and silicon with the chemical formula PuSi. The compound forms gray crystals.
Neptunium(IV) nitrate is an inorganic compound, a salt of neptunium and nitric acid with the chemical formula Np(NO3)4. The compound forms gray crystals, dissolves in water, and forms crystal hydrates.
Silicide carbides or carbide silicides are compounds containing anions composed of silicide (Si4−) and carbide (C4−) or clusters therof. They can be considered as mixed anion compounds or intermetallic compounds, as silicon could be considered as a semimetal.
Neodymium(III) vanadate is an inorganic compound, a salt of neodymium and vanadic acid with the chemical formula of NdVO4. It forms pale-blue, hydrated crystals.
Americium compounds are compounds containing the element americium (Am). These compounds can form in the +2, +3, and +4, although the +3 oxidation state is the most common. The +5, +6 and +7 oxidation states have also been reported.
