MAGNETORESISTANCE BEHAVIOR OF TERNARY RARE-EARTH COMPOUNDS NEAR THE NEEL TEMPERATURE

The results of the magnetoresistance (DELTArho/rho) measurements of th e compounds PrCu2Si2, PrCu1.7Ni0.3Si2, PrCu0.5Ni1.5Si2, GdNi2Si2, GdCu 0.4Ni1.6Si2, and PrCu2Ge2 in the vicinity of the Neel temperature (T(N )) are presented. The magnetoresistance in these samples below T(N) is found to exhibit a variety of behaviors depending upon the magnetic m oment of the rare-earth ions and the position of the Fermi level with respect to the antiferromagnetic energy gap. The results also indicate the existence of short-range magnetic-order effects well above T(N) a nd spin fluctuations (presumably due to Ni) in GdNi2Si2. Features char acterizing the existence of a metamagnetic transition below T(N) in th e PrCU2Ge2 around 15 kOe are also observed. The observations are of re levance to the understanding of magnetoresistance behavior in Ce and U materials.