Defect-induced ferromagnetism in crystalline SrTiO3

In this work it is shown that ion irradiation of high-quality SrTiO3 single crystals can lead to room-temperature ferromagnetism. Structural analysis revealed a polycrystalline SrTiO3 layer, Sr2Ti6O13, or Ruddlesden–Popper like secondary phase at the sample surface induced by their radiation. The lack of any measurable ferromagnetic secondary phases suggests defects are the origin of the observed ferromagnetic signal.