NOVEL HALL-COEFFICIENT BEHAVIOR IN SUPERCONDUCTING SR2RUO4

We present the temperature dependence of the Hall coefficient (R(H)) of Sr2RuO4, in which superconductivity with T-c = 0.93 K has been discovered recently. The value of RH shows strong temperature dependence, and sign reversal occurs at around 20 K, i.e., R(H) is positive and small (less than or equal to 2 x 10(-11) m(3) C-1) for T > 20 K, while for T < 20 K R(H) is negative and \R(H)\ continuously increases at least down to 1.8 K, where R(H) = -1.37 x 10(-10) m(3) C-1. A possible mechanism of the temperature dependence of RH, involving the electron-correlation effect, is discussed.