Magnetoresistance in a well-annealed sample of UCu2Ge2

Results are presented of magnetoresistance measurements in a well-annealed sample of UCu2Ge2. Between the as cast sample and the annealed sample, a si gnificant difference in the low temperature behavior has been observed. A f airly large positive magnetoresistance is observed in the temperature regim e below similar to 50 K in the annealed sample whereas earlier study on the as cast sample had shown a metamagnetic behavior at low temperatures. The measurements suggest the presence of antiferromagnetic interactions in this compound, even in the well-annealed sample, which has been otherwise chara cterized as a ferromagnet. [S0163-1829(99)11725-9].