Magnetic and structural characteristics of RCo{sub 9+{delta}}Si{sub 4} alloys (R=Pr or Gd, {delta}=0{endash}4)

Studies of the magnetic and structural characteristics of RCo{sub 9+{delta}}Si{sub 4} ({delta}=0{endash}4), nonstoichiometric alloys, have been extended from R=La in our earlier work to R=Pr and Gd. In the present work, as the extra Co content increases, the magnetic properties M, T{sub c}, and H{sub c} are significantly enhanced compared to that of the stoichiometric alloys ({delta}=0). Using x-ray diffraction measurements, the sublattice occupancies are calculated. The extra Co atoms are found to occupy the 4a and 16L{sub 2} sites in the Ce{sub 2}Ni{sub 17}Si{sub 9} unit cell. They partially replace R and Si in these sites. {copyright} {ital 1997 American Institute of Physics.}