NORMAL-STATE MAGNETORESISTIVITY OF POLYCRYSTALLINE HONI2B2C

We measured the magnetoresistivity and the magnetization of a HoNi2B2C polycrystalline sample in order to study the superconducting and anti ferromagnetic orderings. In fields higher than the second critical fie ld and up to mu(0)H=2 T, all the normal state magnetoresistivity curve s cross at the same temperature (T congruent to 5.1 K) close to the Ne el temperature T-N. At higher fields this behavior is no longer presen t, probably because the antiferromagnetic order is depressed. For T>5. 1 K the resistivity decreases as the field increases while for T<5.1 K the rho versus H curve is non monotonic and its slope is positive or negative depending on the strength of the magnetic field applied. A pr eliminary explanation of this behavior is proposed. Copyright (C) Publ ished by Elsevier Science Ltd