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- Allotropes_of_boron abstract "Boron can be prepared in several crystalline and amorphous forms. Well known crystalline forms are α-rhombohedral, β-rhombohedral, and β-tetragonal. In special circumstances, boron can also be synthesized in the form of its α-tetragonal, and γ-orthorhombic allotropes. Two amorphous forms, one a finely divided powder and the other a glassy solid, are also known. Although at least 14 more allotropes have been reported, these other forms are based on tenuous evidence or have not been experimentally confirmed, or are thought to represent mixed allotropes, or boron frameworks stabilized by impurities. Whereas the β-rhombohedral phase is the most stable and the others are metastable, the transformation rate is negligible at room temperature, and thus all five phases can exist at ambient conditions. Amorphous powder boron and polycrystalline rhombohedral β-boron are the most common forms. The latter allotrope is a very hard grey material, about ten percent lighter than aluminium and with a melting point (2080 °C) several hundred degrees higher than that of steel.Elemental boron has been found in star dust and meteorites but does not exist in the high oxygen environment of Earth. It is difficult to extract from its compounds. The earliest methods involved reduction of boric oxide with metals such as magnesium or aluminum. However, the product is almost always contaminated with metal borides. Pure boron can be prepared by reducing volatile boron halides with hydrogen at high temperatures. Very pure boron, for use in semiconductor industry, is produced by the decomposition of diborane at high temperatures, followed by purification via zone melting or the Czochralski process. Even more difficult to prepare are single crystals of pure boron phases, due to polymorphism and the tendency of boron to react with impurities; typical crystal size is ~0.1 mm.".
- Allotropes_of_boron thumbnail Brown-boron.jpg?width=300.
- Allotropes_of_boron wikiPageID "22878312".
- Allotropes_of_boron wikiPageLength "27335".
- Allotropes_of_boron wikiPageOutDegree "45".
- Allotropes_of_boron wikiPageRevisionID "698445998".
- Allotropes_of_boron wikiPageWikiLink Ab_initio_quantum_chemistry_methods.
- Allotropes_of_boron wikiPageWikiLink Aluminium.
- Allotropes_of_boron wikiPageWikiLink Amorphous_solid.
- Allotropes_of_boron wikiPageWikiLink Band_gap.
- Allotropes_of_boron wikiPageWikiLink Boride.
- Allotropes_of_boron wikiPageWikiLink Boron.
- Allotropes_of_boron wikiPageWikiLink Boron_carbides.
- Allotropes_of_boron wikiPageWikiLink Boron_trioxide.
- Allotropes_of_boron wikiPageWikiLink Borospherene.
- Allotropes_of_boron wikiPageWikiLink Bulk_modulus.
- Allotropes_of_boron wikiPageWikiLink Category:Allotropy.
- Allotropes_of_boron wikiPageWikiLink Category:Boron.
- Allotropes_of_boron wikiPageWikiLink Chemical_vapor_deposition.
- Allotropes_of_boron wikiPageWikiLink Covalent_bond.
- Allotropes_of_boron wikiPageWikiLink Crystal.
- Allotropes_of_boron wikiPageWikiLink Crystal_structure_prediction.
- Allotropes_of_boron wikiPageWikiLink Crystallite.
- Allotropes_of_boron wikiPageWikiLink Czochralski_process.
- Allotropes_of_boron wikiPageWikiLink Diborane.
- Allotropes_of_boron wikiPageWikiLink Hydrogen.
- Allotropes_of_boron wikiPageWikiLink Icosahedron.
- Allotropes_of_boron wikiPageWikiLink Laser.
- Allotropes_of_boron wikiPageWikiLink Magnesium.
- Allotropes_of_boron wikiPageWikiLink Metal.
- Allotropes_of_boron wikiPageWikiLink Orthorhombic_crystal_system.
- Allotropes_of_boron wikiPageWikiLink Polymorphism_(materials_science).
- Allotropes_of_boron wikiPageWikiLink Rhenium.
- Allotropes_of_boron wikiPageWikiLink Semiconductor.
- Allotropes_of_boron wikiPageWikiLink Sputter_deposition.
- Allotropes_of_boron wikiPageWikiLink Superconductivity.
- Allotropes_of_boron wikiPageWikiLink Tantalum.
- Allotropes_of_boron wikiPageWikiLink Tetragonal_crystal_system.
- Allotropes_of_boron wikiPageWikiLink Trigonal_crystal_system.
- Allotropes_of_boron wikiPageWikiLink Tungsten.
- Allotropes_of_boron wikiPageWikiLink Vickers_hardness_test.
- Allotropes_of_boron wikiPageWikiLink X-ray_crystallography.
- Allotropes_of_boron wikiPageWikiLink Zone_melting.
- Allotropes_of_boron wikiPageWikiLink File:Boron_mNACTEC.jpg.
- Allotropes_of_boron wikiPageWikiLink File:Brown-boron.jpg.
- Allotropes_of_boron wikiPageWikiLink File:GborXRD.JPG.
- Allotropes_of_boron wikiPageWikiLinkText "α-rhombihedral crystal".
- Allotropes_of_boron wikiPageWikiLinkText "Allotropes of boron".
- Allotropes_of_boron wikiPageWikiLinkText "Boron".
- Allotropes_of_boron wikiPageWikiLinkText "allotropes of boron".
- Allotropes_of_boron wikiPageWikiLinkText "red B".
- Allotropes_of_boron wikiPageWikiLinkText "structure for".
- Allotropes_of_boron wikiPageWikiLinkText "α-rhombohedral boron".
- Allotropes_of_boron wikiPageWikiLinkText "α-tetragonal boron".
- Allotropes_of_boron wikiPageWikiLinkText "β-rhombohedral boron".
- Allotropes_of_boron wikiPageWikiLinkText "β-tetragonal boron".
- Allotropes_of_boron colwidth "45".
- Allotropes_of_boron group ""n"".
- Allotropes_of_boron wikiPageUsesTemplate Template:Chem.
- Allotropes_of_boron wikiPageUsesTemplate Template:Cite_book.
- Allotropes_of_boron wikiPageUsesTemplate Template:Cite_journal.
- Allotropes_of_boron wikiPageUsesTemplate Template:Reflist.
- Allotropes_of_boron wikiPageUsesTemplate Template:Sfn.
- Allotropes_of_boron subject Category:Allotropy.
- Allotropes_of_boron subject Category:Boron.
- Allotropes_of_boron type Element.
- Allotropes_of_boron type Metalloid.
- Allotropes_of_boron comment "Boron can be prepared in several crystalline and amorphous forms. Well known crystalline forms are α-rhombohedral, β-rhombohedral, and β-tetragonal. In special circumstances, boron can also be synthesized in the form of its α-tetragonal, and γ-orthorhombic allotropes. Two amorphous forms, one a finely divided powder and the other a glassy solid, are also known.".
- Allotropes_of_boron label "Allotropes of boron".
- Allotropes_of_boron sameAs Q4733226.
- Allotropes_of_boron sameAs ホウ素の同素体.
- Allotropes_of_boron sameAs Q4733226.
- Allotropes_of_boron sameAs 硼的同素異形體.
- Allotropes_of_boron wasDerivedFrom Allotropes_of_boron?oldid=698445998.
- Allotropes_of_boron depiction Brown-boron.jpg.
- Allotropes_of_boron isPrimaryTopicOf Allotropes_of_boron.