Magnetic structure study of SmBaMnO by neutron magnetic diffraction

Kiyanagi, Ryoji  ; Yamada, Shigeki*; Aoki, Hiroshi*; Sagayama, Hajime*; Moyoshi, Taketo*; Nakao, Akiko*; Arima, Takahisa*

The materials represented as ReBaMnO, with an A-site ordered double perovskite structure, exhibit variety of physical orders owing to the competition between charges, orbitals and spins. SmBaMnO shows a charge-orbital order at 380K, a charge-orbital re-arrangement and an antiferromagnetic transition around 200K. In this study, the magnetic structure in the antiferromagnetic phase and the relation between the charge-orbital re-arrangent and the antiferromagnetic phase were investigated by means of neutron magnetic scattering. The measurements were performed on the single crystal neutron diffractometer, SENJU, at J-PARC/MLF. The diffraction pattern revealed magnetic reflections arising from the antiferromagnetic order, which is consistent with the ordering patterns of the charge and the orbitals. The temperature dependences of superlattice reflections and the magnetic reflections clarified that the antiferromagnetic phase transition was triggered by the charge-orbital re-arrangement.