Editing Graphite (section)

===Structure===
Graphite consists of sheets of trigonal planar carbon.<ref>{{cite book |last1=Delhaes |first1=Pierre |chapter=Polymorphism of carbon |editor-last1=Delhaes |editor-first1=Pierre |title=Graphite and precursors |date=2000 |publisher=Gordon & Breach |isbn=9789056992286|pages=1–24}}</ref><ref>{{cite book |last1=Pierson |first1=Hugh O. |title=Handbook of carbon, graphite, diamond, and fullerenes : properties, processing, and applications |date=2012 |publisher=Noyes Publications |isbn=9780815517399 |pages=40–41}}</ref> The individual layers are called [[graphene]]. In each layer, each carbon atom is bonded to three other atoms forming a continuous layer of sp<sup>2</sup> bonded carbon hexagons, like a [[honeycomb lattice]] with a bond length of 0.142&nbsp;nm, and the distance between planes is 0.335&nbsp;nm.<ref>{{cite book |title= Graphite and Precursors |author= Delhaes, P. |publisher= CRC Press |year= 2001 |url= https://books.google.com/books?id=7p2pgNOWPbEC&pg=PA146 |isbn= 978-90-5699-228-6}}</ref> Bonding between layers is relatively weak [[van der Waals force|van der Waals bonds]], which allows the graphene-like layers to be easily separated and to glide past each other.<ref>{{cite journal |last1=Chung |first1=D. D. L. |title=Review Graphite |journal=Journal of Materials Science |date=2002 |volume=37 |issue=8 |pages=1475–1489 |doi=10.1023/A:1014915307738 |s2cid=189839788 }}</ref> Electrical conductivity perpendicular to the layers is consequently about 1000 times lower.<ref>{{Cite book |last=Pierson |first=Hugh O. |url=https://www.worldcat.org/oclc/49708274 |title=Handbook of carbon, graphite, diamond, and fullerenes : properties, processing, and applications |date=1993 |publisher=Noyes Publications |isbn=0-8155-1739-4 |location=Park Ridge, N.J. |oclc=49708274}}</ref>

There are two allotropic forms called ''alpha'' ([[Hexagonal crystal family|hexagonal]]) and ''beta'' ([[Rhombohedral crystal system|rhombohedral]]), differing in terms of the stacking of the graphene layers: stacking in alpha graphite is ABA, as opposed to ABC stacking in the energetically less stable beta graphite. Rhombohedral graphite cannot occur in pure form.<ref name=Gold/> Natural graphite, or commercial natural graphite, contains 5 to 15% rhombohedral graphite<ref name=rhombo>{{Cite journal |last1=Latychevskaia |first1=Tataiana |last2=Son |first2=Seok-Kyun |last3=Yang |first3=Yaping |last4=Chancellor |first4=Dale |last5=Brown |first5=Michael |last6=Ozdemir |first6=Servet |last7=Madan |first7=Ivan |last8=Berruto |first8=Gabriele |last9=Carbone |first9=Fabrizio  |last10=Mishchenko |first10=Artem |last11=Novoselov |first11=Kostya |date=2019-08-17 |title=Stacking transition in rhombohedral graphite |journal=Frontiers of Physics |volume=14 |issue=1 |at=13608 |doi=10.1007/s11467-018-0867-y  |arxiv=1908.06284 |bibcode=2019FrPhy..1413608L |s2cid=125322808}}</ref> and this may be due to intensive milling.<ref>{{cite journal |last1=E. Fitzer |display-authors=etal|title=Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995) |journal=Pure and Applied Chemistry |date=1995 |volume=67 |issue=3 |pages=473–506 |doi=10.1351/pac199567030473 |url=https://www.degruyter.com/document/doi/10.1351/pac199567030473/html}}</ref> The alpha form can be converted to the beta form through shear forces, and the beta form reverts to the alpha form when it is heated to 1300&nbsp;°C for four hours.<ref name=rhombo/><ref name=Gold>{{GoldBookRef |file=R05385 |title=Rhombohedral graphite}}</ref>

<gallery perrow="6">
File:Graphite ambient STM.jpg|[[Scanning tunneling microscope]] image of graphite surface
File:Graphite-layers-side-3D-balls.png|Side view of ABA layer stacking
File:Graphite-layers-top-3D-balls.png|Plane view of layer stacking
File:Graphite-unit-cell-3D-balls.png|Alpha graphite's [[unit cell]] 
</gallery>