Editing Pyroelectricity (section)

== Pyroelectric materials ==
Although artificial pyroelectric materials have been engineered, the effect was first discovered in minerals such as [[tourmaline]]. The pyroelectric effect is also present in [[bone]] and [[tendon]].<ref>{{Cite journal|last=LANG|first=SIDNEY B.|date=November 1966|title=Pyroelectric Effect in Bone and Tendon|url=http://dx.doi.org/10.1038/212704a0|journal=Nature|volume=212|issue=5063|pages=704–705|doi=10.1038/212704a0|bibcode=1966Natur.212..704L |s2cid=4205482 |issn=0028-0836|url-access=subscription}}</ref>

The most important example is [[gallium nitride]], a semiconductor.<ref>Gallium Nitride (GaN): Physics, Devices, and Technology." 2015. CRC Press. October 16</ref> The large electric fields in this material are detrimental in light emitting diodes (LEDs), but useful for the production of power transistors.{{Citation needed|date=December 2022}}

Progress has been made in creating artificial pyroelectric materials, usually in the form of a thin film, using [[gallium nitride]] ([[Gallium|Ga]][[Nitrogen|N]]), [[caesium nitrate]] ([[Caesium|Cs]][[Nitrogen|N]][[Oxygen|O]]<sub>3</sub>), [[polyvinyl fluoride]]s, derivatives of [[phenylpyridine]], and [[cobalt]] [[phthalocyanine]]. [[Lithium tantalate]] ([[Lithium|Li]][[Tantalum|Ta]][[Oxygen|O]]<sub>3</sub>) is a crystal exhibiting both [[piezoelectric]] and pyroelectric properties, which has been used to create small-scale [[nuclear fusion]] ("[[pyroelectric fusion]]").<ref name="NaranjoGimzewski2005">{{cite journal|last1=Naranjo|first1=B.|last2=Gimzewski|first2=J.K.|last3=Putterman|first3=S.|title=Observation of nuclear fusion driven by a pyroelectric crystal|journal=Nature|volume=434|issue=7037|year=2005|pages=1115–1117|issn=0028-0836|doi=10.1038/nature03575|pmid=15858570|bibcode = 2005Natur.434.1115N |s2cid=4407334}}</ref> Recently, pyroelectric and piezoelectric properties have been discovered in doped [[hafnium oxide]] ([[Hafnium|Hf]][[Oxygen|O]]<sub>2</sub>), which is a standard material in [[CMOS]] manufacturing.<ref>{{cite journal|last1=Mart|first1=C.|last2=Kämpfe|first2=T.|last3=Hoffmann|first3=R.|last4=Eßlinger|first4=S.|last5=Kirbach|first5=S.|last6=Kühnel|first6=K.|last7=Czernohorsky|first7=M.|last8=Eng|first8=L.M.|last9=Weinreich|first9=W.|title=Piezoelectric Response of Polycrystalline Silicon-Doped Hafnium Oxide Thin Films Determined by Rapid Temperature Cycles|journal=Advanced Electronic Materials|volume=6|issue=3|year=2020|pages=1901015|doi=10.1002/aelm.201901015|doi-access=free}}</ref>