J Phys Condens Matter. 2023 Dec 18. doi: 10.1088/1361-648X/ad16ac. Online ahead of print.
ABSTRACT
We systematically investigate the long- and short-range chemical order, lattice volume, and spontaneous magnetization in single-crystalline Fe0.6Al0.4compound thin films. The vapor-quenching method based on a molecular beam epitaxy technique is utilized to fabricate the single-crystalline Fe0.6Al0.4compound with the differentB2 long-range order parameterS.Swas varied by the deposition temperatureTd, and it increases with increasingTd. The lattice volumeVdecreased with increasingTd, while the tetragonal distortion, ~4%, due to epitaxial strain were observed. The changes inSandVwere accompanied with the change in the magnetic moment per Fe,μFe.μFeshowed the monotonic decrease as a function ofSwhereasμFemonotonically increases withV. With considering tetragonal distortion,μFe–Vrelationship has a good agreement with the previous reports. TheμFe–Srelationship showed the steep decrease ofμFearoundS~0.6. In contrast toμFe–Vrelationship,μFe–Srelationship does not match only from ours to previous studies but also among other reports. It implies the statistical number of the nearest-neighbor Fe-Fe bonds,i.e.S, cannot be an enough explanatory parameter. To clarify the structural origin of change inμFe, the short-range order parameter inferred from the analysis of superlattice diffractions were introduced. They showed the clear difference for the films with high and lowμFe. The results suggest that the transition from the long- to the short-range order state plays the significant role onμFe.
PMID:38112082 | DOI:10.1088/1361-648X/ad16ac
