HALL-EFFECT IN THE 2-DIMENSIONAL METAL SR2RUO4

We report a detailed study of the Hall effect in Sr2RuO4, the first la yered perovskite superconductor which does not contain copper (T-c con gruent to 1 K). The Hall coefficient (R(H)) was measured at temperatur es between 20 mK and 300 K, and an unusual dependence of R(H) on the a pplied magnetic field was observed. R(H) has a strong temperature depe ndence below 25 K, but below 1 K it saturates at a value of -1.15x10(- 10) m(3)/C. The Fermi surface of Sr2RuO4 is known from quantum oscilla tion measurements, and since it is nearly two dimensional, it is possi ble to derive a simple expression for R(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 R(H) on the basis of the known Fermi surface parameters.