  Short-range ordering (SRO) tendency for disordered alloys is considered as
competition between chemical ordering and geometric (mainly, difference in
atomic radius for constituents) effects. Especially for multicomponent
(including the so-called high entropy alloys (HEAs) near equiatomic
composition), it has been considered as difficult to systematically
characterize the SRO tendency only by geometric effects, due mainly to the fact
that (i) chemical effects typically plays significant role, (ii) near
equiatomic composition, we cannnot classify which elements belong to solute or
solvent, and (iii) underlying lattice for pure elements can typically differ
from each other. Despite these facts, we here show that SRO tendency for seven
fcc-based alloys including subsystems of Ni-based HEAs, can be well
characterized by geometric effects, where corresponding atomic radius is
defined based on atomic configuration with special fluctuation, measured from
ideally random structure. The present findings strongly indicate the
significant role of geometry in underlying lattice on SRO for multicomponent
alloys.
