Ferroelectricity and weak ferromagnetism of hexagonal ErFeO 3 thin films

Hiroko Yokota (1) , Tomoya Nozue (1) , Shin Nakamura (2, 3) , Hajime Hojo (4) , Mamoru Fukunaga (5) , Pierre-Eymeric Janolin (6) , Jean-Michel Kiat (6, 7) , Akio Fuwa (8)

1 Chiba University
2 Department of Science and Engineering, Tochigi
3 Advance Research Center of Science and Engineering, waseda
4 Materials and structures Laboratory, Kanagawa
5 Department of Physics, Okayama University
6 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides
7 LLB - UMR 12 - Laboratoire Léon Brillouin
8 Department of Science and Engineering [University of Waseda]

Hexagonal ErFeO 3 thin films fabricated by a pulsed laser deposition method were investigated by x-ray diffraction (XRD) and transmission electron microscopy. No structural phase transition was observed between 20 and 900 K. Ferroelectric D-E hysteresis loops were obtained at room temperature using the double-wave method, and the magnitude of spontaneous polarization was determined to be 200 nC/cm 2. The existence of superlattice reflections in the XRD indicates that the space group of ErFeO 3 thin film is the polar hexagonal P 6 3 cm. This result also supports the ferroelectricity at room temperature. Magnetic properties were examined by a superconducting quantum interference device and Mössbauer spectroscopy. Below the Néel temperature of 120 K (T N), a weak ferromagnetism appears along the c axis due to the canting of Fe 3+ magnetic moments. Around T N , the imaginary part of dielectric constant shows an anomaly. These results prove h-ErFeO 3 thin films to be multiferroic below 120 K.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Hiroko Yokota, Tomoya Nozue, Shin Nakamura, Hajime Hojo, Mamoru Fukunaga, et al.. Ferroelectricity and weak ferromagnetism of hexagonal ErFeO 3 thin films. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2015, 92, pp.054101. ⟨10.1103/PhysRevB.92.054101⟩. ⟨hal-01259816⟩