<article_title>Boron_nitride</article_title>
<edit_user>Polyparadigm</edit_user>
<edit_time>Sunday, February 13, 2005 11:42:21 PM CET</edit_time>
<edit_comment>practical considerations, BN nanotubes</edit_comment>
<edit_text>|} Boron nitride is a binary chemical compound, consisting of equal proportions of boron and nitrogen, with composition BN. Structurally, it is isoelectronic to carbon and takes on similar physical forms: a graphite-like one, and a diamond-like one. The latter is one of the hardest materials known, behind diamond and ultrahard fullerite. It is widely used for grinding and as material for tools in industry<strong>, partly because it does not dissolve into [[iron]], [[nickel]] and related [[alloys]] at high temperatures, but diamond does</strong>. Theoretical beta carbon nitride is thought to be harder. Hexagonal boron nitride finds use as a high-temperature lubricant where the electrical conductivity or reactivity of graphite would be problematic.</edit_text>
<turn_user>Polyparadigm<turn_user>
<turn_time>Sunday, February 13, 2005 11:28:39 PM CET</turn_time>
<turn_topicname>Graphite-like, diamond-like</turn_topicname>
<turn_topictext>I'd rather call it hexagonal and cubic. Maybe leave graphite-like as a remark, but the 'diamond-like' phase is cubic (contary to tetrahedal bonded diamond). Also in the Material-properties template under appearance the two modifications should be mentioned. --Dschwen 07:16, 12 Jan 2005 (UTC) "Diamond cubic" is the name of the crystaline structure of most semiconductors, including diamond, BN, and SiC, and Si. Yes, the bonding is tetrahedral; in fact, tetrahedral symmetry is only found in cubic systems (look down the corner of a cube if you don't see the 3-fold axis at first).--Polyparadigm 23:27, 13 Feb 2005 (UTC)</turn_topictext>
<turn_text>"Diamond cubic" is the name of the crystaline structure of most semiconductors, including diamond, BN, and SiC, and Si. Yes, the bonding is tetrahedral; in fact, tetrahedral symmetry is only found in cubic systems (look down the corner of a cube if you don't see the 3-fold axis at first).</turn_text>