Electronics & Semiconductors

Fermi-level tuning to improve the stability of 2D graphene-based FETs

Two-dimensional (2D) semiconductors are a class of semiconducting materials with thicknesses on the atomic scale. These materials have numerous advantageous properties, including good mobilities at thicknesses below 1 nm, ...

Electronics & Semiconductors

Radiation-immune and repairable chips to fabricate durable electronics

To operate safely and reliably in outdoor environments, electronic devices should be resistant to a wide variety of external factors, including radiation. In fact, high-energy radiation can damage several components of field-effect ...

Engineering

New organic-metal oxide transistors with high operational stability

Metal oxide thin-film transistors (TFTs), which are built by depositing thin films of an active metal oxide-based semiconducting material on a supporting substrate, have become widely used over the past few years, particularly ...

Electronics & Semiconductors

Building a 900-pixel imaging sensor using an atomically thin material

A team of researchers at Penn State University has developed a 900-pixel imaging sensor using an atomically thin material. In their paper published in the journal Nature Materials, the group describes how they built their ...

Electronics & Semiconductors

An indium oxide-based transistor created using atomic layer deposition

Over the past decades, engineers have created increasingly advanced and highly performing integrated circuits (ICs). The rising performance of these circuits in turn increased the speed and efficiency of the technology we ...

Hardware

High-speed 3-D memory with ferroelectric NAND flash memory

Ferroelectric memory is a well-researched topic in the past decade due to its capacity for higher speed, lower power consumption and longer endurance, compared to conventional flash memory. The performance of ferroelectric ...

page 1 from 11

Oxide

An oxide ( /ˈɒksaɪd/) is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2.

Most of the Earth's crust consists of solid 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 consists 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. Finely grained powders of most metals can be dangerously explosive in air. Consequently, they are often used in Solid-fuel rockets.

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. Noble metals (such as gold or platinum) resist direct chemical combination with oxygen, and substances like gold(III) oxide must be generated by indirect routes.

This text uses material from Wikipedia, licensed under CC BY-SA