Ordering and magnetostriction in Fe alloy single crystals

Short-range and long-range ordering in α-Fe terminal solid solution phase (A2 phase with bcc structure) influences its physical, mechanical, magnetic and magnetostrictive behavior. Single crystal sample forms are ideal for examining order in these alloys using X-ray and neutron scattering techniques. Limited structural information available suggests that the lattice of A2 phase at room temperature contains a mixture of regions with local atomic environments similar to those expected in the long-range ordered structures in stable/metastable equilibrium with the A2 phase. The nature and extent of these regions are sensitive to alloy composition and the thermal history. The lattice strain modulations result from the nature of solute atom distribution (short-range ordering) in each region and impact the physical, mechanical, corrosion and magnetic behaviors. A need for a fundamental understanding of ordering in Fe and other alloys through structural evaluations of local atomic environments in alloy single crystals is suggested in this review. ► A review of nature of ordering in bcc lattices of Fe-based alloys is presented. ► Analysis of ordering in Fe alloy single crystals using data from XRD and other methods. ► Current understanding of ordering and its influence on magnetostriction in Fe alloys is presented. ► Lattice strain modulations from the nature of solute atom distribution impact magnetostriction. ► Need for examinations of local atomic environments and ordering using single crystals emphasized.