Neutron scattering study of yttrium iron garnet

Shamoto, Shinichi  ; Ito, Takashi   ; Onishi, Hiroaki  ; Yamauchi, Hiroki   ; Inamura, Yasuhiro  ; Matsuura, Masato*; Akatsu, Mitsuhiro*; Kodama, Katsuaki   ; Nakao, Akiko*; Moyoshi, Taketo*; Munakata, Koji*; Ohara, Takashi   ; Nakamura, Mitsutaka   ; Kawamura, Seiko   ; Nemoto, Yuichi*; Shibata, Kaoru  

Nuclear and magnetic structure and full magnon dispersions of yttrium iron garnet YFeO have been studied by neutron scattering. The lowest-energy dispersion below 14 meV exhibits a quadratic dispersion as expected from ferromagnetic magnons. The imaginary part of -integrated dynamical spin susceptibility "() exhibits a square-root energy-dependence in the low energies. The magnon density of state is estimated from the "() obtained on an absolute scale. The value is consistent with a single chirality mode for the magnon branch expected theoretically.