This section deals with specific problems occuring when stepping a variable in a system with a miscibility gap.

WHICH MODULE ? mu
MULTIPHASE OPTION ? def sy 'Fe,Ni,Nb,C' sou plus !
MULTIPHASE OPTION ? cl ab p(*) misc(FCC_A1) 1 !
MULTIPHASE OPTION ? set w 100 !
MULTIPHASE OPTION ? set w( ) undef 20 0.5 0.05 !
MULTIPHASE OPTION ? step temp 973 1273 25 !
MULTIPHASE OPTION ? co pri gra !
MULTIPHASE OPTION ? ord n p log yes !
MULTIPHASE OPTION ? plot go

As expected, there are two phases forming with the FCC_A1 structure: austenite and NbC. To convince yourself of the nature of the second FCC_A1, do the following:

MULTIPHASE OPTION ? set temp 1073 !
MULTIPHASE OPTION ? co pri ea_st_re !

We now want to produce a graph of the carbon content of the austenite:

MULTIPHASE OPTION ? step temp 973 1273 25 !
MULTIPHASE OPTION ? co pri gra !
MULTIPHASE OPTION ? ordinate comp_dist moles_in_phase(FCC_A1,1) !
MULTIPHASE OPTION ? ord n p log yes !
MULTIPHASE OPTION ? plot go

Note the (FCC_A1,1) which refers to the first phase forming in FCC_A1.