Synthesis, structure and physical properties of U3Co2Si7 and Np3Co2Si7 compounds

A new ternary compound Np3Co2Si7 was found to crystallize in the orthorhombic La3Co2Sn7-type structure, space group Cmmm (N¿65) with room temperature lattice parameters determined from powder diffraction as follows: a = 4.000 (1) °A, b = 24.491 (8) °A, c= 4.020 (2) °A, (V = 393.8 °A3). Np3Co2Si7 orders ferromagnetically with a Curie temperature of about 32 K. U3Co2Si7 has also been prepared for comparison. It is isostructural to Np3Co2Si7 with lattice parameters a = 4.010 (6) °A, b = 24.389 (2) °A, c = 4.022 (5) °A. An annealing of U3Co2Si7 at 1223 K for 10 days is required to obtain it as a single phase. U3Co2Si7 was reported in the literature as a ferromagnet. However, our measurements show a paramagnetic behavior and the presence of a weak ferromagnetic impurity.

ELOIRDI Rachel; 

2010-07-19

IOP Publishing

JRC56417

http://iopscience.iop.org/1742-6596/200/3/032017,    https://publications.jrc.ec.europa.eu/repository/handle/JRC56417,   

10.1088/1742-6596/200/3/032017,