about RE bontain alloy in melting and freezing

Hello all
 recently,I‘m focusing on the effect of RE(La、Ce)in alloy. First of all, I want to  figure out RE's behavior and effect during the melting alloy freezing procedure。So Lammps came to my mind, I think Lammps  can simulate melting/freezing well. But,here is my question,how can I get the Binary alloy (such as Fe-La,Fe-Ce) potential files ? I have checked through http://www.ctcms.nist.gov/potentials/, this site doesn't publish such files.
best regards
gao xueyun

Please search the literature.