Oxide
hideAn oxide is a chemical compound contaning at least one oxygen atom as well as at least one other element. Most of the Earth's crust consists of oxides. Oxides result when elements are oxidized by oxygen in air. Combustion of hydrocarbons affords the two principal oxides of carbon, carbon monoxide and carbon dioxide. Even materials that are considered to be pure elements often contain a coating of oxides. For example, aluminium foil has a thin skin of Al2O3 that protects the foil from further corrosion.
Virtually all elements burn in an atmosphere of oxygen, or an oxygen rich environment. In the presence of water and oxygen (or simply air), some elements - lithium, sodium, potassium, rubidium, caesium, strontium and barium - react rapidly, even dangerously, to give the hydroxides. In part for this reason, alkali and alkaline earth metals are not found in nature in their metallic, i.e., native, form. Caesium is so reactive with oxygen that it is used as a getter in vacuum tubes, and solutions of potassium and sodium, so called NaK are used to deoxygenate and dehydrate some organic solvents. The surface of most metals consist of oxides and hydroxides in the presence of air. A well known example is aluminium foil, which is coated with a thin film of aluminium oxide that passivates the metal, slowing further corrosion. The aluminium oxide layer can be built to greater thickness by the process of electrolytic anodising. Although solid magnesium and aluminium react slowly with oxygen at STP, they, like most metals, will burn in air, generating very high temperatures. As a consequence, finely grained powders of most metals can be dangerously explosive in air.
In dry oxygen, iron readily forms iron(II) oxide, but the formation of the hydrated ferric oxides, Fe2O3−2x(OH)x, that mainly comprise rust, typically requires oxygen and water. The production of free oxygen by photosynthetic bacteria some 3.5 billion years ago precipitated iron out of solution in the oceans as Fe2O3 in the economically-important iron ore hematite.
Due to its electronegativity, oxygen forms chemical bonds with almost all elements to give the corresponding oxides. So-called noble metals (common examples: gold, platinum) resist direct chemical combination with oxygen, and substances like gold(III) oxide must be generated by indirect routes.
For more information about Oxide, read the full article at
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News tagged with metal oxide
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A multidisciplinary team of UC researchers is the first to find an innovative and novel way to control an electron's spin orientation using purely electrical means.
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(PhysOrg.com) -- European researchers have created a world-leading camera in CMOS that can record photons at a million times a second. Best of all, it will be really cheap to manufacture, offering applications ...
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Flying high over the Gulf of Mexico, researchers from NASA and Case Western Reserve University found a key to unlocking oxygen from the surface of the moon.
SKoreans demonstrate spin-injected field effect transistor
Sep 18, 2009 |
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South Korean scientists said Friday they had demonstrated a spin-injected field effect transistor in a high-mobility InAs heterostructure.
Truth Is Stranger Than Science: Discovering true properties of metal oxides
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(PhysOrg.com) -- To successfully compete in a global marketplace, manufacturers continually search for better materials: faster drying and less hazardous paint, longer-lasting sunscreen, and faster computers. ...
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Researchers from the Eindhoven University of Technology and the University of Ulm have made the first high-resolution 3D images of the inside of a polymer solar cell. This gives them important new insights ...
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Researchers at the National Institute of Standards and Technology have developed a new calibration technique that will improve the reliability and stability of one of NIST's most versatile technologies, the ...
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Customers want fresh food, which is neither unripe nor spoiled. A new system based on metal oxide sensors could check the safety and quality of foods reliably, quickly and economically -- such as how ripe ...
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(PhysOrg.com) -- Ph.D. candidate Sataporn Pornpromlikit played a critical role in research at UC San Diego that made a big impact at a recent conference, and might provide manufacturers with the means for making cell phones ...
45-nanometer chips for ultra-fast WiFi
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(PhysOrg.com) -- Powerful new radio technologies that promise blisteringly fast WiFi have been given a boost by a team of European researchers’ cutting-edge work on miniscule microchips.
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(PhysOrg.com) -- Scientists from CSIRO's Food Futures Flagship have made a breakthrough in efforts to extend the sensory range of 'electronic noses' (e-noses) by developing a system for comparing their performance ...
'Holey' Nanosheets for Wastewater Dye Removal
Nanotechnology / Nanomaterials
Jul 01, 2009 |
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(PhysOrg.com) -- Researchers have discovered that extremely thin sheets of nickel oxide with hexagonally shaped holes can absorb hazardous dyes from wastewater nearly as well as the best traditional methods, but are recyclable. ...
A quicker, cheaper SARS virus detector -- one easily customizable for other targets
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Members of a USC-led research team say they've made a big improvement in a new breed of electronic detectors for viruses and other biological materials — one that may be a valuable addition to the battle against ...
Terahertz Waves Are Effective Probes for IC Heat Barriers
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(PhysOrg.com) -- By modifying a commonly used commercial infrared spectrometer to allow operation at long-wave terahertz frequencies, researchers at the National Institute of Standards and Technology discovered ...
IBM Alliance Announces Availability of Advanced 28-Nanometer, Low-Power Semiconductor Technology
Apr 20, 2009 |
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IBM, Chartered Semiconductor Manufacturing, GLOBALFOUNDRIES, Infineon Technologies, Samsung Electronics, and STMicroelectronics have defined and are jointly developing a 28-nanometer, high-k metal gate (HKMG), low-power bulk ...
