It has been well established that both in bulk at ambient pressure and for
films under modest strains, cubic SrCoO3−δ (δ<0.2) is a
ferromagnetic metal. Recent theoretical work, however, indicates that a
magnetic phase transition to an antiferromagnetic structure could occur under
large strain accompanied by a metal-insulator transition. We have observed a
strain-induced ferromagnetic to antiferromagnetic phase transition in
SrCoO3−δ films grown on DyScO3 substrates, which provide a large
tensile epitaxial strain, as compared to ferromagnetic films under lower
tensile strain on SrTiO3 substrates. Magnetometry results demonstrate the
existence of antiferromagnetic spin correlations and neutron diffraction
experiments provide a direct evidence for a G-type antiferromagnetic structure
with Ne\'el temperatures between TN∼135±10K and ∼325±10K depending on the oxygen content of the samples. Therefore, our
data experimentally confirm the predicted strain-induced magnetic phase
transition to an antiferromagnetic state for SrCoO3−δ thin films
under large epitaxial strain.Comment: 6 pages, 4 figure