Complexity in the structural and magnetic properties of almost multiferroic EuTiO3

In a number of recent publications hidden magnetic properties at high temperatures have been reported for EuTiO3 (ETO), which orders antiferromagnetically below T-N = 5.7K. In addition, structural phase transitions have been discovered which correlate with the magnetic responses and can be tuned by a magnetic field. In order to identify the magnetic properties of ETO at temperatures well above T-N, low-energy muon-spin rotation (mu SR) experiments have been performed on thin films of ETO which exhibit all properties observed in bulk materials and are thus well suited to conclude about the magnetic order of the bulk. The mu SR data reveal anomalies at 282 and 200 K related to the structural phase transitions in accordance with birefringence results. In addition, a transition to some kind of magnetic order below 100 K was observed as previously indirectly deduced from conductivity and dielectric constant measurements.