Editing Pyrochlore (section)

==Crystal structure==
The more general crystal structure describes materials of the type A<sub>2</sub>B<sub>2</sub>O<sub>6</sub> and A<sub>2</sub>B<sub>2</sub>O<sub>7</sub> where the A and B species are generally rare-earth or transition metal species; e.g. Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>.The pyrochlore structure is a super structure derivative of the simple [[fluorite structure]] (AO<sub>2</sub> = A<sub>4</sub>O<sub>8</sub>), where the A and B cations are ordered along the {{angbr|110}} direction. The additional anion vacancy resides in the tetrahedral interstice between adjacent B-site cations. These systems are particularly susceptible to [[geometrical frustration]] and novel magnetic effects.

The pyrochlore structure shows varied physical properties spanning electronic [[Insulator (electricity)|insulators]] (e.g. La<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub>), [[Ionic conductivity (solid state)|ionic conductors]] (Gd<sub>1.9</sub>Ca<sub>0.1</sub>Ti<sub>2</sub>O<sub>6.9</sub>), [[Electrical conductivity#In metals|metallic conductors]] (Bi<sub>2</sub>Ru<sub>2</sub>O<sub>7−''y''</sub>), mixed ionic and electronic conductors, [[spin ice]] systems (Dy<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>), [[spin glass]] systems (Y<sub>2</sub>Mo<sub>2</sub>O<sub>7</sub>), haldane chain systems (Tl<sub>2</sub>Ru<sub>2</sub>O<sub>7</sub>) and [[Superconductivity|superconducting materials]] (Cd<sub>2</sub>Re<sub>2</sub>O<sub>7</sub>).<ref>{{Cite journal |last1=Subramanian |first1=M. A. |last2=Aravamudan |first2=G. |last3=Subba Rao |first3=G. V. |date=1983-01-01 |title=Oxide pyrochlores — A review |journal=Progress in Solid State Chemistry |volume=15 |issue=2 |pages=55–143 |doi=10.1016/0079-6786(83)90001-8}}</ref> More disordered structures, such as the bismuth pyrochlores,<ref>Arenas, D. J., et al. "Raman study of phonon modes in bismuth pyrochlores." Physical Review B 82.21 (2010): 214302. | https://doi.org/10.1103/PhysRevB.82.214302</ref> have also been investigated due to interesting high-frequency dielectric properties.<ref>Cann, David P., [[Clive Randall|Clive A. Randall]], and Thomas R. Shrout. "Investigation of the dielectric properties of bismuth pyrochlores." Solid state communications 100.7 (1996): 529–534. | https://doi.org/10.1016/0038-1098(96)00012-9</ref>

The crystal structure has been investigated for use in solid electrolytes for [[Lithium-ion battery|lithium iron batteries]]. It is alleged to provide high conductivity while inhibiting dendrite growth.<ref>{{Cite web |last=Ettlin |first=Anna |date=2023-11-07 |title=What Is The Battery Of The Future Made Of? |url=https://cleantechnica.com/2023/11/07/what-is-the-battery-of-the-future-made-of/ |access-date=2023-11-15 |website=CleanTechnica |language=en-US}}</ref>