MAGNETIC-PROPERTIES OF 2 NEW COMPOUNDS - GD2NI3SI5 AND SM2NI3SI5

The formation of two new materials, SM2Ni3Si5 and Gd2Ni3Si5, of the rare-earth series R2M3Si5 (R denotes rare earth and Y) and their magnetic and transport properties are reported here. These materials crystallize in the orthorhombic U2Co3Si5-type structure (space group Ibam). The magnetic susceptibility of Gd2Ni3Si5 follows a Curie-Weiss behavior with an effective magnetic moment 8.1mu(B)/Gd ion. The material orders antiferromagnetically at almost-equal-to 15 K. The magnetic susceptibility of Sm2Ni3Si5 exhibits a deviation from the Curie-Weiss behavior which is attributed to the low-lying excited state of Sm3+ ions and also to crystal-field effects. This material also orders antiferromagnetically, but at almost-equal-to 11 K. This value of the ordering temperature does not seem to follow the de Gennes scaling with respect to that of Gd