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Many superconductors are non-stoichiometric. For example, yttrium barium copper oxide, arguably the most notable high-temperature superconductor, is a non-stoichiometric solid with the formula Y x Ba 2 Cu 3 O 7−x. The critical temperature of the superconductor depends on the exact value of x.
Gas blending is the process of mixing gases for a specific purpose where the composition of the resulting mixture is defined, and therefore, controlled. A wide range of applications include scientific and industrial processes, food production and storage and breathing gases.
Its thermal conductivity (2,200 W/m•K) is five times greater than the most conductive metal (Ag at 429); 300 times higher than the least conductive metal (Pu at 6.74); and nearly 4,000 times that of water (0.58) and 100,000 times that of air (0.0224). This high thermal conductivity is used by jewelers and gemologists to separate diamonds from ...
Liquid phase of MON contains no nitric oxide. [2] N 2 O 4 ⇌ 2NO 2. NO 2 + NO ⇌ N 2 O 3. A broad range of compositions is available, and can be denoted as MONi, where i represents the percentage of nitric oxide in the mixture (e.g. MON3 contains 3% nitric oxide, MON25 25% nitric oxide). An upper limit is MON40 (40% by weight).
For example, an NMC molar composition of 33% nickel, 33% manganese, and 33% cobalt would abbreviate to NMC111 (also NMC333 or NCM333) and have a chemical formula of LiNi 0.33 Mn 0.33 Co 0.33 O 2. A composition of 50% nickel, 30% manganese, and 20% cobalt would be called NMC532 (or NCM523) and have the formula LiNi 0.5 Mn 0.3 Co 0.2 O 2.
Although most metal oxides are crystalline solids, many non-metal oxides are molecules. Examples of molecular oxides are carbon dioxide and carbon monoxide. All simple oxides of nitrogen are molecular, e.g., NO, N 2 O, NO 2 and N 2 O 4. Phosphorus pentoxide is a more complex molecular oxide with a deceptive name, the real formula being P 4 O 10.
Cerium(IV) oxide ("ceria") has the fluorite structure, similarly to the dioxides of praseodymium and terbium. Ceria is a nonstoichiometric compound, meaning that the real formula is CeO 2−x, where x is about 0.2. Thus, the material is not perfectly described as Ce(IV). Ceria reduces to cerium(III) oxide with hydrogen gas. [25]
Perovskite are mixed metal oxide with a well-defined cubic structure and a general formula of ABO 3, where A is an alkaline earth or lanthanide element and B is a transition metal. These materials are attractive for CO 2 separation because of the tunability of the metal sites as well as their stabilities at elevated temperatures.