Magnetic-field-induced magnetic phase transitions associated with ferroelectricity in multiferroic ErMnO

Kimura, Hiroyuki*; Wakimoto, Shuichi  ; Fukunaga, Mamoru*; Noda, Yukio*; Kaneko, Koji   ; Metoki, Naoto   ; Kakurai, Kazuhisa; Kay, Kohn*

Microscopic magnetic properties under the application of a magnetic field were investigated in multiferroic ErMnO using neutron diffraction. Below = 8K upon applying a magnetic field along the -axis, an incommensurate-commensurate-incommensurate magnetic phase transition occurred. On the contrary, when the magnetic field was applied parallel to the -axis, no phase transition occurred up to = 5T. - phase diagrams obtained in the present study show a one-to-one correspondence with - phase diagrams for previously obtained dielectric properties, indicating that the field-induced dielectric transition was triggered by magnetic phase transition. The contrastive phase diagram between ∥ and ∥ suggests that the induced Er magnetic moment contributed significantly to the magnetic and dielectric responses to the magnetic field.