Magnetostriction of Fe100−xVx alloys for 5.2 ⩽ x ⩽ 40.7

Highlights: ► The magnetostriction in the α-phase Fe–V alloys vs vanadium concentration presents two maxima, at 11.8%V and 30.7%V (at.%). ► The maximum total magnetostriction was 69 ppm for Fe88.2V11.8 alloy and a lattice contraction occurs at this composition. ► The Fe88.2V11.8 lattice contraction is due to hybridization between minority spin d subbands, stronger Fe–V interactions. -- Abstract: We investigate the magnetostriction of polycrystalline Fe100−xVx alloys as a function of vanadium content, with values of x varying from 5.2% to 40.7% (at.%V). The lattice parameter curve behavior as a function of vanadium deviates from a linear behavior at x ≈ 10.2 and x ≈ 30.7. Close to x = 10.2 is possible to observe a small lattice contraction and close to x = 30.7 an expansion. The magnetostriction curve as a function of vanadium content shows two maxima at x = 11.8 and 30.7 and has values of 3/2λs of 68.8 ppm and 49.3, respectively. The alloys microstructures investigations do not offer enough elements to connect it with magnetostriction. Therefore first-principles calculations were performed and resulted that the lattice contraction at ∼10.2% of V is due to the formation of strengthened Fe–V interactions associated to stronger hybridization between minority spin d subbands, while the lattice expansion observed in the range 25.5–30.7% of V is associated to the weakening of the Fe–V interaction. As for the case of simulating V–V pairs for the alloy Fe12V4, representative of x = 25.0, we associated the experimental result of the lattice expansion observed in the range among 25.5–30.7% of V to the weakening of the Fe–V interaction. These calculated electronic properties explain the lattice contraction (at x = 10.2) and expansion (x = 25.5–30.7) and are expected to be the sources of the magnetostrictive behavior of these Fe–V alloys