What is chromium oxide? Chrome oxidegreen is also known as "chrome oxide," commonly known as "chrome green." Dark green hexagonal crystal or amorphous powder. Its melting point is 2435 ℃, its boiling point is 4000 ℃, its relative density is 5.21, and its refractive index is 2.551. Its hydrate is known as "water chrome green," a purple amorphous crystal or blue-grey green gel. It is insoluble in water, acid, and alkali and can be soluble in hot potassium bromate. Its property is extremely stable; even if hydrogen is introduced at high temperatures, it will not change. Preparation method: sodium dichromate reacts with sulfur, Or it is obtained by heating and decomposing chromium hydroxide and ammonium dichromate. Use: as a pigment, organic synthesis catalyst, ceramic glaze, paint raw material, and raw material for making chromium alloy and chromium salt.
Preparation of chromium oxide Generally, CrO2 can be prepared by the thermal decomposition of CrO3. Since the end point of thermal decomposition is Cr2O3, a certain oxygen pressure must be maintained to obtain CrO2. However, CrO2 suitable for magnetic tape needs to be prepared in two steps (1) 1.01 at 250 ℃ × Heat CrO3 at 105Pa oxygen pressure or Cr (NO3) 3 · 9H2O at 250~400 ℃. After a few days, the value of CrxOy.2y/x is between 4 and 6; the average oxidation number is between 5.00 and 5.33. This CrxOy has less water solubility than CrO3 and can be used for the hydrothermal method (2) CrxOy obtained in the above step is used as raw material, and water or acid solution is used as reaction medium, at 250~500 ℃, 5.1 × 106~3 × Preparation at 108Pa. The high-pressure decomposition of CrO3 can also prepare CrO2 in the presence of water vapor or the thermal decomposition of CrO2Cl2.
Structure of chromium oxide CrO2 has a tetragonal rutile structure; the space group is P4/nmn, a=0.4421nm, c=0.2917nm. Cr atoms are located at the center and corner of the crystal cell. The density is 4.9g/cm3. CrO2 is metastable in the air. If there is no Cr2O3 crystal nucleus in the lattice, it can be heated for a long time at 400 ℃ (more than 48h). For example, at (6.0~6.4) × Under the pressure of 109Pa, it can be heated at 1200 ℃ for more than 60 min and heated at 2000 ℃ for 2 min without decomposition. However, when the Cr2O3 crystal nucleus is mixed, the thermal decomposition temperature will be reduced. There have been reports of decomposition at 250~500 ℃ in the past. CrO2 has strong magnetism (Curie temperature 126 ℃), and the saturation magnetic flux density is 0.61T. It is a metallic conductor, and the resistivity of powder accumulation is 4 × 10-2～2 × 10-3 Ω· cm, single crystal {100} plane resistivity is (2.5 ± 0.5) × 10-4Ω·cm.
Price of chromium oxide Chromium oxide particle size and purity will affect the product's price, and the purchase volume can also affect the cost of chromium oxide. A large amount of large amount will be lower. The price of chromium oxide can be found on our company's official website.
Chromium oxide supplier Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) Luoyang City, Henan Province, China, is a reliable and high-quality global chemical material supplier and manufacturer. It has more than 12 years of experience providing ultra-high quality chemicals and nanotechnology materials, including chromium oxide, nitride powder, graphite powder, sulfide powder, and 3D printing powder. If you are looking for high-quality and cost-effective chromium oxide, you are welcome to contact us or inquireat any time.
