on LSAT (001): field-polarized long-range order and interfacial ferromagnetism

EuTiO₃ thin films have recently been reported to manifest complex magnetotransport phenomena upon carrier substitution, ranging from symmetry breaking anisotropic magnetoresistance to nonmonotonic anomalous Hall transport. Here we investigate the interplay between magnetism and transport behavior by studying the evolution of magnetic order in thin film samples of biaxially strained and electron-doped EuTiO₃ under an applied field. Neutron diffraction reveals that G-type antiferromagnetism is suppressed with the onset of in-plane field-polarized ferromagnetism for insulating, semimetallic, and metallic samples. However, polarized neutron reflectometry further reveals the onset of interfacial ferromagnetism at low fields far below the fully polarized state. The relationship between magnetic order and electron transport behavior associated with the Weyl semimetal phase in these films will be discussed.