Large Low Temperature Magnetoresistance and Magnetic Anomalies in Tb$_2$PdSi$_3$ and Dy$_2$PdSi$_3$
arXiv:cond-mat/9811387 · doi:10.1016/S0038-1098(98)00012-X
Abstract
The results of heat-capacity, magnetic susceptibility, electrical resistivity and magnetoresistance $(ÎÏ/Ï)$ measurements on the compounds Tb$_2$PdSi$_3$ and Dy$_2$PdSi$_3$, are reported. The results establish that these compounds undergo long-range magnetic ordering (presumably with a complex magnetic structure) below (Tc=) 23 and 8 K respectively. The $ÎÏ/Ï$ is negative in the vicinity of Tc and the magnitude grows as Tc is approached from higher temperature as in the case of well-known giant magnetoresistance systems (La manganite based perovskites); this is attributed to the formation of some kind of magnetic polarons. The magnitude of magnetoresistance at low temperatures is quite large, for instance, about 30% in the presence of 60 kOe field at 5 K in the Dy sample.
4 pages, 3 figures, RevTex