'''Strontium ruthenate''' (SROSrO) is an [[oxide]] of [[strontium]] and [[ruthenium]] with the [[chemical formula]] Sr<sub>2</sub>RuO<sub>4</sub>. It was the first reported [[Perovskite (structure)|perovskite]] [[superconductor]] that did not contain [[copper]].<ref name=maeno1994 /><ref name=yanoff2000>{{cite book|last=Yanoff|first=Brian|title=Temperature dependence of the penetration depth in the unconventional superconductor Sr2RuO4|year=2000|publisher=University of Illinois at Urbana-Champaign|url=http://groups.mrl.uiuc.edu/dvh/theses/yanoff.pdf}}</ref> Strontium ruthenate is structurally very similar to the [[High-temperature superconductivity#Cuprates|high-temperature cuprate]] superconductors,<ref name=wooten>{{cite web|last=Wooten|first=Rachel|title=Strontium Ruthenate|url=https://docs.google.com/viewer?a=v&q=cache:DgnknpjYbx4J:sces.phys.utk.edu/~dagotto/condensed/HW2_2008/Strontium_Ruthenate.ppt+&hl=en&gl=us&pid=bl&srcid=ADGEESjZ7iZGRQSADAb7Z1s_9eAna1xiWVss132uKFgZzdWLT0aMoimFedsvEYqudjD3jQQnZj0ttTougqs1felMdAWruV20EbFHDcoyabxp8gHZE7bmi1WI28B0Y5qLzU42RqJuuJwO&sig=AHIEtbTQVVf6y8oDl63wDTUkXKH9NrNEug&pli=1|publisher=University of Tennessee-Knoxville|access-date=16 April 2012}}</ref> and in particular, is almost identical to the [[lanthanum]] doped superconductor (La, Sr)<sub>2</sub>CuO<sub>4</sub>.<ref name=maeno2001>{{cite journal|last=Maeno|first=Yoshiteru|author2=Maurice Rice |author3=Manfred Sigrist |title=The intriguing superconductivity of Strontium Ruthenate|journal=Physics Today|year=2001|volume=54|issue=1|doi=10.1063/1.1349611|url=http://www.physics.mcmaster.ca/~imai/PhysicsToday_2001.pdf|access-date=16 April 2012|bibcode = 2001PhT....54a..42M|pages=42 |doi-access=free}}</ref> However, the [[critical temperature|transition temperature]] for the superconducting phase transition is 0.93 [[Kelvin|K]] (about 1.5 [[Kelvin|K]] for the best sample), which is much lower than the corresponding value for cuprates.<ref name=maeno1994>{{cite journal|last=Maeno|first=Yoshiteru|author2=H. Hashimoto |title=Superconductivity in a layered perovskite without copper|journal=Nature|year=1994|volume=372|pages=532–534|doi=10.1038/372532a0|bibcode = 1994Natur.372..532M|issue=6506 |s2cid=4303356|display-authors=etal}}</ref>
High-quality crystals of strontium ruthenate are synthesized using a [[floating zone method]] in a controlled atmosphere with ruthenium as flux. The perovskite structure can be deduced based on [[powder diffraction|powder x-ray diffraction]] measurements. Strontium ruthenate behaves as a conventional [[Fermi liquid]] at temperatures below 25 K.<ref name=yanoff2000 />
