Electrical resistivity of UNi2Si2 in magnetic fields

We report on electrical resistivity measurements for an UNi2Si2 single crys tal in the temperature range 4.2-140 K and magnetic fields up to 8.4 T para llel to the c axis. The anomalies in the temperature and field dependencies of the resistivity are associated with magnetic phase transitions and allo w one to complete the B-T magnetic phase diagram. The relationship between the electrical resistivity and the periodicity of particular magnetic phase s is discussed in light of magnetoresistance behavior in other antiferromag netic U compounds. (C) 1999 American Institute of Physics. [S0021-8979(99)3 4908-2].