Multi-step magnetic transitions in EuNiIn

Ikeda, Shugo*; Kaneko, Koji   ; Tanaka, Yuki*; Kawasaki, Takuro   ; Hanashima, Takayasu*; Munakata, Koji*; Nakao, Akiko*; Kiyanagi, Ryoji  ; Ohara, Takashi   ; Mochizuki, Kensei*; Kondo, Akihiro*; Kindo, Koichi*; Homma, Yoshiya*; Frontzek, M. D.*; Kobayashi, Hisao*

Magnetism in EuNiIn has been studied by specific heat, magnetic susceptibility, magnetization, Eu Mssbauer spectroscopy, and neutron diffraction experiments. The specific heat shows two magnetic transitions at and at zero magnetic field. An antiferromagnetic ground state of EuNiIn has a uniaxial magnetic anisotropy along the b-axis, revealed by the magnetic susceptibility and the Mssbauer spectroscopy. Single crystal neutron diffraction experiments clarify that this antiferromagnetic structure in the ground state is characterized by the commensurate propagation vector = (1/2, 1/2, 1/2) which reveals no distinct anomaly at . The magnetization curve along the b-axis at 2 K shows four successive magnetic field-induced transitions up to 50 kOe and, reaches 7 /f.u. above 190 kOe, The magnetic phase diagram in EuNiIn has unique characteristics with five magnetic states in low magnetic field.