Unexpected magnetism at high temperature and novel magneto-dielectric-elastic coupling in EuTiO3: A critical review

Perovskite oxides ABO3 offer a vast playground for applications and basic research. Especially multifunctionality is a frequently targeted aim, since the replacement of the A and/or B sublattice ions easily changes the properties of the system. Here we concentrate on the perovskite EuTiO3 (ETO) which was ignored by the scientific community for a long time. We review recent results on it and show that this compound provides many surprises which may offer novel device techniques and applications. In particular we demonstrate that far above its Néel temperature TN = 5.7 K magnetism exists and new magneto-dielectric-elastic coupling is at work. From capacitance and muon spin rotation (μSR) data we conclude that the phase diagram of ETO is much more complex than believed and a variety of new phases are described.