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β-tin, also called white tin, is the allotrope (structural form) of elemental tin that is stable at and above room temperature. It is metallic and malleable, and has body-centered tetragonal crystal structure. α-tin, or gray tin , is the nonmetallic form.
At 13.2 °C (55.8 °F) and below, pure tin transforms from the silvery, ductile metallic allotrope of β-form white tin to the brittle, nonmetallic, α-form grey tin with a diamond cubic structure. The transformation is slow to initiate due to a high activation energy but the presence of germanium (or crystal structures of similar form and size ...
The amorphous allotrope is a brown powder. The crystalline allotrope is gray and has a metallic luster. [16] Tin has two allotropes: α-tin, also known as gray tin, and β-tin. Tin is typically found in the β-tin form, a silvery metal. However, at standard pressure, β-tin converts to α-tin, a gray powder, at temperatures below 13.2 °C (55.8 ...
White tin may also refer specifically to β-tin, the metallic allotrope of the pure element, as opposed to the nonmetallic allotrope α-tin (also known as gray tin), which occurs at temperatures below 13.2 °C (55.8 °F), a transformation known as tin pest). White tin has tetragonal unit cell.
Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in crystalline structure.. Allotropy or allotropism (from Ancient Greek ἄλλος (allos) 'other' and τρόπος (tropos) 'manner, form') is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements.
Carbide-derived carbon (CDC) is a family of carbon materials with different surface geometries and carbon ordering that are produced via selective removal of metals from metal carbide precursors, such as TiC, SiC, Ti 3 AlC 2, Mo 2 C, etc. This synthesis is accomplished using chlorine treatment, hydrothermal synthesis, or high-temperature ...
The most stable form is the black allotrope, which is a metallic looking, brittle and relatively non-reactive semiconductor (unlike the white allotrope, which has a white or yellowish appearance, is pliable, highly reactive and a semiconductor). When assessing periodicity in the physical properties of the elements it needs to be borne in mind ...
These materials were found to be stable up to at least 350 tons/cm 2 (34.3 GPa). [44] Icosahedral or distorted-icosahedral fullerene-like complexes have also been prepared for germanium, tin, and lead; some of these complexes are spacious enough to hold most transition metal atoms. [45] [46]