Low Field Magnetic Susceptibility of Sm_1-xLu_xS and Sm_1-xGd_xS

Abstract

Low field magnetic susceptibility of Sm1-xLuxS at x = 0.30 and 0.40 and Sm1-xGdxS at x = 0.17 and 0.35 have been investigated in the temperature range 4.2-300 K. The Lu and Gd atoms are found to simulate the effect of pressure on pure SmS. In both the alloys systems, the mixed valence state of Sm ions are found to be consistent with that estimated from lattice parameter determinations. In addition it is shown from the magnetic susceptibility studies that the fractional valence state achieved on chemically inducing the collapsed metallics phase of sms, is determined by the electronic structure of the doped rare earth ions. No magnetic ordering of the Gd ions is found to the lowest temperatures studied in the Sm1-xGdxS alloys.