We report a detailed study of the Hall effect in ${\mathrm{Sr}}_2$${\mathrm{RuO}}_4$, the first layered perovskite superconductor which does not contain copper (${\mathit{T}}_{\mathit{c}}$≃1 K). The Hall coefficient (${\mathit{R}}_{\mathit{H}}$) was measured at temperatures between 20 mK and 300 K, and an unusual dependence of ${\mathit{R}}_{\mathit{H}}$ on the applied magnetic field was observed. ${\mathit{R}}_{\mathit{H}}$ has a strong temperature dependence below 25 K, but below 1 K it saturates at a value of -1.15×${10}^{\mathrm{-}10}$ ${\mathrm{m}}^3$/C. The Fermi surface of ${\mathrm{Sr}}_2$${\mathrm{RuO}}_4$ is known from quantum oscillation measurements, and since it is nearly two dimensional, it is possible to derive a simple expression for ${\mathit{R}}_{\mathit{H}}$ using methods developed by Ong [Phys. Rev. B 43, 193 (1991)]. We show that if the mean free path, l, is assumed to be isotropic at low temperatures, it is possible to make an accurate quantitative calculation of ${\mathit{R}}_{\mathit{H}}$ on the basis of the known Fermi surface parameters. © 1996 The American Physical Society.

• Received 4 March 1996

DOI:https://doi.org/10.1103/PhysRevB.54.7425