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The '''hafnium nitrides''' are the various [[Salt (chemistry)|salts]] produced from combining [[hafnium]] and [[nitrogen]]. The two most important such are hafnium(III) nitride, HfN; and hafnium(IV) nitride, Hf<sub>3</sub>N<sub>4</sub>. None can be prepared from [[hafnium oxide]], but must instead be prepared from the elemental metal or a different hafnium nitride salt; attempted nitridation of the oxide gives an [[oxynitride]] instead.<ref>{{Cite journal |last=Bazhanov |first=D. I. |last2=Knizhnik |first2=A. A. |last3=Safonov |first3=A. A. |last4=Bagatur’yants |first4=A. A. |last5=Stoker |first5=M. W. |last6=Korkin |first6=A. A. |date=2005-02-15 |title=Structure and electronic properties of zirconium and hafnium nitrides and oxynitrides |url=https://pubs.aip.org/jap/article/97/4/044108/914354/Structure-and-electronic-properties-of-zirconium |journal=Journal of Applied Physics |language=en |volume=97 |issue=4 |doi=10.1063/1.1851000 |issn=0021-8979}}</ref>
HfN is [[refractory]] and generally produced as a [[thin film]] coating,<ref name=":0">{{Cite journal |last=Zerr |first=Andreas |last2=Miehe |first2=Gerhard |last3=Riedel |first3=Ralf |date=2003-03-01 |title=Synthesis of cubic zirconium and hafnium nitride having Th3P4 structure |url=https://www.nature.com/articles/nmat836 |journal=Nature Materials |language=en |volume=2 |issue=3 |pages=185–189 |doi=10.1038/nmat836 |issn=1476-1122}}</ref> although [[zone annealing]] gives the bulk material.<ref>{{Cite journal |last=Christensen |first=A. Nørlund |last2=Kress |first2=W. |last3=Miura |first3=M. |last4=Lehner |first4=N. |date=1983-07-15 |title=Phonon anomalies in transition-metal nitrides: HfN |url=https://link.aps.org/doi/10.1103/PhysRevB.28.977 |journal=Physical Review B |language=en |volume=28 |issue=2 |pages=977–981 |doi=10.1103/PhysRevB.28.977 |issn=0163-1829}}</ref> HfN adopts the [[Rock-salt structure|rock-salt crystal structure]].<ref name=":0" /> The surplus hafnium electron [[Delocalized electron|delocalizes]], so that HfN is a [[metal]], [[Electrical conductor|conducting]] at [[room temperature]] and [[superconducting]] below {{Convert|8.8|K|F|abbr=on}}. Its bright [[Gold (color)|gold color]] is a cheaper alternative to [[gilding]].<ref name=":1">{{Cite journal |last=Kroll |first=Peter |date=2003-03-25 |title=Hafnium Nitride with Thorium Phosphide Structure: Physical Properties and an Assessment of the Hf-N, Zr-N, and Ti-N Phase Diagrams at High Pressures and Temperatures |url=https://link.aps.org/doi/10.1103/PhysRevLett.90.125501 |journal=Physical Review Letters |language=en |volume=90 |issue=12 |doi=10.1103/PhysRevLett.90.125501 |issn=0031-9007}}</ref>
The [[dark red]] semiconductor Hf<sub>3</sub>N<sub>4</sub> does not form at room temperature, but requires [[high pressure]], high temperature synthesis in a [[diamond anvil cell]]. At {{Convert|18|GPa|atm|abbr=on}} and {{Convert|2800|K|F|abbr=on}}, it adopts the cubic crystal structure and repeats according to [[space group]] I{{Overline|1 (Repeating)=4}}3d.<ref name=":0" /> At lower pressures, the cubic structure is believed [[metastable]], decaying to the [[Orthorhombic crystal system|orthorhombic]] structure of [[zirconium(IV) nitride]].<ref name=":1" /><ref name=":2">{{Cite journal |last=Zhang |first=Jin |last2=Oganov |first2=Artem R. |last3=Li |first3=Xinfeng |last4=Niu |first4=Haiyang |date=2017-01-18 |title=Pressure-stabilized hafnium nitrides and their properties |url=https://link.aps.org/doi/10.1103/PhysRevB.95.020103 |journal=Physical Review B |language=en |volume=95 |issue=2 |doi=10.1103/PhysRevB.95.020103 |issn=2469-9950}}</ref> That structure forms outright at 19 GPa and {{Convert|2000|K|F|abbr=on}}, and another metastable [[Tetragonal crystal system|tetragonal]] structure forms at 12 GPa and {{Convert|1500|K|F|abbr=on}}. [[Simulation|Computational studies]] suggest that it may catalyze [[polymerization]] of [[nitrogen]] at very high temperatures, through a [[Catenation|catenary]] anion in HfN<sub>10</sub>.<ref name=":2" />
In systems with limited nitrogen, hafnium also forms Hf<sub>3</sub>N<sub>2</sub>, as well as a [[solid solution]] hafnium [[alloy]].<ref>{{Cite journal |last=Ushakov |first=Sergey V. |last2=Navrotsky |first2=Alexandra |last3=Hong |first3=Qi-Jun |last4=van de Walle |first4=Axel |date=26 Aug 2019 |orig-date=6 Aug 2019 |title=Carbides and nitrides of zirconium and hafnium |journal=Materials |location=Basel |publisher=[[MDPI]] |volume=2019 |issue=12 |doi=10.3390/ma12172728 |doi-access=free}}</ref>
== References ==
<references />
{{Inorganic-compound-stub}}
[[Category:Hafnium compounds]]
[[Category:Nitrides]]
[[Category:Salts]]
[[Category:Refractory materials]]
Okumaya devam et...
The '''hafnium nitrides''' are the various [[Salt (chemistry)|salts]] produced from combining [[hafnium]] and [[nitrogen]]. The two most important such are hafnium(III) nitride, HfN; and hafnium(IV) nitride, Hf<sub>3</sub>N<sub>4</sub>. None can be prepared from [[hafnium oxide]], but must instead be prepared from the elemental metal or a different hafnium nitride salt; attempted nitridation of the oxide gives an [[oxynitride]] instead.<ref>{{Cite journal |last=Bazhanov |first=D. I. |last2=Knizhnik |first2=A. A. |last3=Safonov |first3=A. A. |last4=Bagatur’yants |first4=A. A. |last5=Stoker |first5=M. W. |last6=Korkin |first6=A. A. |date=2005-02-15 |title=Structure and electronic properties of zirconium and hafnium nitrides and oxynitrides |url=https://pubs.aip.org/jap/article/97/4/044108/914354/Structure-and-electronic-properties-of-zirconium |journal=Journal of Applied Physics |language=en |volume=97 |issue=4 |doi=10.1063/1.1851000 |issn=0021-8979}}</ref>
HfN is [[refractory]] and generally produced as a [[thin film]] coating,<ref name=":0">{{Cite journal |last=Zerr |first=Andreas |last2=Miehe |first2=Gerhard |last3=Riedel |first3=Ralf |date=2003-03-01 |title=Synthesis of cubic zirconium and hafnium nitride having Th3P4 structure |url=https://www.nature.com/articles/nmat836 |journal=Nature Materials |language=en |volume=2 |issue=3 |pages=185–189 |doi=10.1038/nmat836 |issn=1476-1122}}</ref> although [[zone annealing]] gives the bulk material.<ref>{{Cite journal |last=Christensen |first=A. Nørlund |last2=Kress |first2=W. |last3=Miura |first3=M. |last4=Lehner |first4=N. |date=1983-07-15 |title=Phonon anomalies in transition-metal nitrides: HfN |url=https://link.aps.org/doi/10.1103/PhysRevB.28.977 |journal=Physical Review B |language=en |volume=28 |issue=2 |pages=977–981 |doi=10.1103/PhysRevB.28.977 |issn=0163-1829}}</ref> HfN adopts the [[Rock-salt structure|rock-salt crystal structure]].<ref name=":0" /> The surplus hafnium electron [[Delocalized electron|delocalizes]], so that HfN is a [[metal]], [[Electrical conductor|conducting]] at [[room temperature]] and [[superconducting]] below {{Convert|8.8|K|F|abbr=on}}. Its bright [[Gold (color)|gold color]] is a cheaper alternative to [[gilding]].<ref name=":1">{{Cite journal |last=Kroll |first=Peter |date=2003-03-25 |title=Hafnium Nitride with Thorium Phosphide Structure: Physical Properties and an Assessment of the Hf-N, Zr-N, and Ti-N Phase Diagrams at High Pressures and Temperatures |url=https://link.aps.org/doi/10.1103/PhysRevLett.90.125501 |journal=Physical Review Letters |language=en |volume=90 |issue=12 |doi=10.1103/PhysRevLett.90.125501 |issn=0031-9007}}</ref>
The [[dark red]] semiconductor Hf<sub>3</sub>N<sub>4</sub> does not form at room temperature, but requires [[high pressure]], high temperature synthesis in a [[diamond anvil cell]]. At {{Convert|18|GPa|atm|abbr=on}} and {{Convert|2800|K|F|abbr=on}}, it adopts the cubic crystal structure and repeats according to [[space group]] I{{Overline|1 (Repeating)=4}}3d.<ref name=":0" /> At lower pressures, the cubic structure is believed [[metastable]], decaying to the [[Orthorhombic crystal system|orthorhombic]] structure of [[zirconium(IV) nitride]].<ref name=":1" /><ref name=":2">{{Cite journal |last=Zhang |first=Jin |last2=Oganov |first2=Artem R. |last3=Li |first3=Xinfeng |last4=Niu |first4=Haiyang |date=2017-01-18 |title=Pressure-stabilized hafnium nitrides and their properties |url=https://link.aps.org/doi/10.1103/PhysRevB.95.020103 |journal=Physical Review B |language=en |volume=95 |issue=2 |doi=10.1103/PhysRevB.95.020103 |issn=2469-9950}}</ref> That structure forms outright at 19 GPa and {{Convert|2000|K|F|abbr=on}}, and another metastable [[Tetragonal crystal system|tetragonal]] structure forms at 12 GPa and {{Convert|1500|K|F|abbr=on}}. [[Simulation|Computational studies]] suggest that it may catalyze [[polymerization]] of [[nitrogen]] at very high temperatures, through a [[Catenation|catenary]] anion in HfN<sub>10</sub>.<ref name=":2" />
In systems with limited nitrogen, hafnium also forms Hf<sub>3</sub>N<sub>2</sub>, as well as a [[solid solution]] hafnium [[alloy]].<ref>{{Cite journal |last=Ushakov |first=Sergey V. |last2=Navrotsky |first2=Alexandra |last3=Hong |first3=Qi-Jun |last4=van de Walle |first4=Axel |date=26 Aug 2019 |orig-date=6 Aug 2019 |title=Carbides and nitrides of zirconium and hafnium |journal=Materials |location=Basel |publisher=[[MDPI]] |volume=2019 |issue=12 |doi=10.3390/ma12172728 |doi-access=free}}</ref>
== References ==
<references />
{{Inorganic-compound-stub}}
[[Category:Hafnium compounds]]
[[Category:Nitrides]]
[[Category:Salts]]
[[Category:Refractory materials]]
Okumaya devam et...