Evidence for an extended critical region near the metamagnetic transition of UCoAl

Electrical resistivity and ac magnetic susceptibility studies of the 5f-metamagnet UCoAl reveal the presence of strong spin fluctuation effects for temperatures below 30 K and magnetic fields below the critical metamagnetic field mu(0)H(c) approximate to 1 T, where a non-Fermi liquid term similar to T-3/2 is prominent in the electrical resistivity. A step-wise increase of the residual resistivity and an increasingly prominent Fermi liquid T-2 term of the resistivity is observed as the field is increased though the metamagnetic transition. (C) 1998 American Institute of Physics. [S0021-8979(98)43411-X].