STRUCTURAL AND MAGNETIC-PROPERTIES OF LAFE13-XSIX NITRIDES

LAFe13-xSix compounds were found to have two types of crystal structur e; the face-centered cubic NaZn13-type (x less-than-or-equal-to 2.4) a nd the body-centered tetragonal Ce2Ni17Si9-type (3.5 less-than-or-equa l-to x less-than-or-equal-to 5.0). Nitrogenation has a strong effect o n the cubic phase, including a large lattice expansion (6.2 to 10.8 %) , an increase of Curie temperature (52 to 80 K) and spontaneous magnet ization (approximately 10 %). The tetragonal phase, however, was not s ignificantly affected by the nitrogenation.