Critical behavior of magnetization in URhAl; Quasi-two-dimensional Ising system with long-range interactions

Tateiwa, Naoyuki   ; Pospil, J.*; Haga, Yoshinori   ; Yamamoto, Etsuji  

The critical behavior of dc magnetization in the uranium ferromagnet URhAl with the hexagonal ZrNiAl-type crystal structure has been studied around the ferromagnetic transition temperature . The critical exponent for the temperature dependence of the spontaneous magnetization below , for the magnetic susceptibility, and for the magnetic isotherm at have been obtained. We have determined the critical exponents as = 0.287 0.005, = 1.47 0.02, and = 6.08 0.04 by the scaling analysis and the critical isotherm analysis. These critical exponents satisfy the Widom scaling law . The determined exponents can be explained with the results of the renormalization group approach for a two-dimensional Ising system coupled with long-range interactions.