Enhanced Spin‐Reorientation Transition and Polarization in DyFeO 3 Thin Films
Banani Biswas, Bixin Yan, Morgan Trassin, Dirk Fuchs, Ekatarina V. Pomjakushina, Manfred Fiebig, Thomas Lippert, Christof W. SchneiderABSTRACT
Epitaxial strain in antiferromagnetic orthoferrite thin films is predicted to significantly enhance magnetic and polar properties with a shift of the polar response from below 4 K to room temperature and above by strengthening the rare earth‐Fe interaction. In DyFeO 3 , the Fe‐spins undergo a spin reorientation transition between 40–50 K, and a magnetic field‐induced ferroelectric phase transition is triggered by Dy ordering and displacement below 4 K. Here we report an increase in the spin reorientation temperature by more than 20 K in compressively strained DyFeO 3 films. The expected sharp spin transition is several 10 K wide, incomplete and largely suppressed, with the magnetic point group remaining at Γ 4 at all temperatures. The strain‐induced Dy ordering above 4 K reduces the magnetic symmetry and introduces room‐temperature polar order with the electrical polarization vector oriented along [100] and polarization values of more than 3 µC/cm 2 .