Mh. Gerdes et al., MAGNETIC AND ELECTRICAL-PROPERTIES OF A NEW SERIES OF RARE-EARTH SILICIDE CARBIDES WITH THE COMPOSITION R3SI2C2 (R = Y, LA-ND, SM, GD-TM), Journal of solid state chemistry (Print), 138(2), 1998, pp. 201-206
The 12 title compounds have been prepared by arc-melting cold-pressed
pellets of the elemental components and subsequent annealing, They cry
stallize with an orthorhombic structure and with cell dimensions varyi
ng between a = 403.9(1) pm, b = 1688.4(2) pm, and c = 450.6(1) pm for
La3Si2C2 and a = 379.6(1) pm, b = 1532.8(2) pm, and c = 414.5(1) pm fo
r Tm3Si2C2, The magnetic properties of these compounds were determined
with a SQUID magnetometer between 2 and 300 K with magnetic flux dens
ities up to 5.5 T. Y3Si2C2 is a Pauli paramagnet. The cerium atoms in
Ce3Si2C2 are trivalent; at low temperatures this compound is ferro- or
ferrimagnetic with an ordering temperature of 10(+/-3) K. Pr3Si2C2 an
d Nd3Si2C2 are ferromagnetic (T-C = 25(+/-3) and 30(+/-3) K, respectiv
ely), whereas the silicide carbides R3Si2C2 with R = Sm and Gd-Tm are
antiferromagnetic. Ho3Si2C2, Er3Si2C2, and Tm3Si2C2 show metamagnetic
transitions. The highest ordering temperature occurs for Gd3Si2C2 with
a Neel temperature T-N = 50(+/-1) K, The electrical conductivities of
several compounds were determined between 5 and 300 K, They indicate
metallic behavior, and in several cases they reflect the magnetic orde
ring temperatures. (C) 1998 Academic Press.