Microscopic investigation of antiferromagnetic order in A-site-ordered perovskite manganite YBaMn2O6

The electromagnetic properties of the A-site-ordered perovskite manganite YBaMn2O6 have been investigated by 55Mn-NMR and μSRμSR measurements. 55Mn-NMR spectrum of YBaMn2O6 at the ground state is consistent with a charge-ordered antiferromagnetic state, where egeg-electrons of Mn3+Mn3+ ions are well localized. In the antiferromagnetic state, three components of muon spin oscillation are observed in the μSRμSR time spectra. The observed muon spin oscillating frequencies are consistently explained by the checker-board-type charge order and the antiferromagnetic spin order proposed by the previous neutron diffraction study. The most probable candidate for the muon site is near O(7) in the BaO plane of YBaMn2O6.