Magnetic Properties of Liquid 3d Transition Metal-Ge Alloys

The magnetic susceptibilities (chi) of liquid Ti-Ge and V-Ge alloys show a weak and positive temperature dependence in restricted regions of up to 30 at.% Ti and 40 at.% V, respectively. This suggests that the Ti and V ions in these liquid alloys are in a nonmagnetic state. The chi values of liquid TM-Ge (TM = Fe, Co, Ni) alloys on the Ge-rich side exhibit a similar temperature dependence. The data in the nonmagnetic state were analyzed using the Anderson model. In the nonmagnetic state, we found smooth variations in which both the effective intra-atomic d-d interaction and the density of 3d states at the Fermi level E-F decrease with increasing E-F of liquid TM0.1M0.9 (M = Sn -> Ge -> Si) alloys. Liquid Cr1-cGec with c >= 0.7 and Mn1-cGec with c >= 0.3 obeyed the Curie-Weiss law with regard to the temperature dependence of their chi. The composition dependences of the chi of liquid Cr-Ge and Mn-Ge alloys show maxima at compositions of 50 at.% Cr and 70 at.% Mn, respectively. The magnetic susceptibilities of liquid Fe1-cGec with c <= 0.7, liquid Co1-cGec with c <= 0.3, and liquid Ni1-cGec with c <= 0.1 also exhibited a Curie-Weiss-type behavior. We compared the effective number of Bohr magnetons of liquid TM-Ge alloys with those of liquid TM-Sn and TM-Si alloys at the same TM composition and also investigated the relationship between chi(3d) and E-F for liquid TM0.5M0.5 alloys.