Editing Boron nitride (section)

===Pyrolytic boron nitride (PBN)===

Pyrolytic boron nitride (PBN), also known as [[Chemical vapor deposition|Chemical vapour-deposited]] Boron Nitride(CVD-BN),<ref>{{cite web |url=https://www.preciseceramic.com/blog/introduction-of-pyrolytic-boron-nitride-pbn.html |title=About Pyrolytic Boron Nitride |last=Rose |first=Lisa |website=Precise Ceramic |access-date=May 31, 2024}}</ref> is a high-purity [[ceramic]] material characterized by exceptional chemical resistance and mechanical strength at high temperatures.<ref>{{cite web |title=Pyrolytic Boron Nitride (PBN) |url=https://www.shinetsu.co.jp/en/products/electronics-materials/pyrolytic-boron-nitride-pbn/ |website=Shin-Etsu Chemical Co., Ltd. |access-date=May 31, 2024}}</ref>
Pyrolytic boron nitride is typically prepared through the thermal decomposition of [[boron trichloride]] and [[ammonia]] vapors on [[graphite]] substrates at 1900&nbsp;°C.<ref>{{cite journal |last1=Moore |first1=A. |title=Compression Annealing of Pyrolytic Boron Nitride |journal=Nature |volume=221 |pages=1133–1135 |date=1969-03-22 |issue=5186 |doi=10.1038/2211133a0 |bibcode=1969Natur.221.1133M |url=https://www.nature.com/articles/2211133a0 |access-date=May 31, 2024}}</ref>

Pyrolytic boron nitride (PBN) generally has a hexagonal structure similar to hexagonal boron nitride (hBN), though it can exhibit stacking faults or deviations from the ideal lattice.<ref>{{cite web |title=An Overview of Pyrolytic Boron Nitride (PBN) |url=https://www.sputtertargets.net/an-overview-of-pyrolytic-boron-nitride-pbn.html |website=Sputter Targets |date=3 December 2018 |access-date=May 31, 2024}}</ref> Pyrolytic boron nitride (PBN) shows some remarkable attributes, including exceptional chemical inertness, high [[dielectric]] strength, excellent thermal shock resistance, non-wettability, non-toxicity, oxidation resistance, and minimal [[outgassing]].
<ref>{{cite journal |last1=Lipp |first1=A. |last2=Schwetz |first2=K.A. |last3=Hunold |first3=K. |title=Hexagonal boron nitride: Fabrication, properties and applications |journal=Journal of the European Ceramic Society |volume=5 |issue=1 |pages=3–9 |date=1989 |doi=10.1016/0955-2219(89)90003-4 }}</ref><ref>{{cite journal |last1=Moore |first1=A.W. |title=Characterization of pyrolytic boron nitride for semiconductor materials processing |journal=Journal of Crystal Growth |volume=106 |issue=1 |pages=6–15 |date=1990 |doi=10.1016/0022-0248(90)90281-O |bibcode=1990JCrGr.106....6M }}</ref>

Due to a highly ordered planar texture similar to pyrolytic graphite (PG), it exhibits anisotropic properties such as lower [[dielectric]] constant vertical to the [[crystal]] plane and higher bending strength along the [[crystal]] plane.<ref>{{cite journal |last1=Rebillat |first1=F. |last2=Guette |first2=A. |title=Highly ordered pyrolytic BN obtained by LPCVD |journal=Journal of the European Ceramic Society |volume=17 |issue=12 |pages=1403–1414 |date=1997 |doi=10.1016/S0955-2219(96)00244-0}}</ref> PBN material has been widely manufactured as [[crucibles]] of compound [[semiconductor]] crystals, output windows and [[dielectric]] rods of traveling-wave tubes, high-temperature [[Jig (tool)|jigs]] and [[Insulator (electricity)|insulator]].<ref>{{cite journal |last1=Gao |first1=Shitao |last2=Li |first2=Bin |title=Micromorphology and structure of pyrolytic boron nitride synthesized by chemical vapor deposition from borazine |journal=Ceramics International |volume=44 |issue=10 |pages=11424–11430 |date=2018 |doi=10.1016/j.ceramint.2018.03.201}}</ref>