Chemical trend of nonanalytic short-range order in body-centered cubic alloys

Nonanalytic chemical short-range order (SRO) has been experimentally observed in face-centered cubic (fcc) alloys, but has seldom been reported for body-centered cubic alloys. However, it is still unclear what causes this qualitative difference. Here, we systematically assess the chemical trends of nonanalytic chemical SRO in bcc alloys based on a rigorous analytic derivation. We find that similar to fcc alloys, the nonanalytic chemical SRO in bcc alloys is also primarily characterized by elastic anisotropy and shear stiffness of the host lattice. But different from fcc alloys, there are more bcc alloys that are closer to be elastically isotropic, leading to weaker nonanalyticities. We further extend our analysis to the nonanalytic SRO in bcc medium- and high-entropy alloys using our formalism, which also exhibit different sets of behaviors for the nonanalyticity. These insights improve our understanding of the chemical SRO in metallic alloys, constituting a basis for manipulating alloy properties through engineering local chemical order.