We have measured the magnetization of single crystalline Sr3Fe2O6.5 with a lot of oxygen deficiencies. It was observed that the spin direction is parallel to the c-axis below TN. Moreover, we carried out neutron powder diffraction experiments with a Sr3Fe2O6.21 powder sample. The magnetic structure with a lot of oxygen deficiencies (δ > 0.5) has a typical Ising antiferromagnet system with the magnetic unit cell √2a × √2a × c. On the other hand, it was found that the magnetic structure of Sr3Fe2O6.94 with a few oxygen deficiencies is larger than that of 2a × 2a × 4c. The magnetic structure of Sr3Fe2O6.94 is obviously different from that of Sr3Fe2O7-δ (δ > 0.5). Such a difference in the magnetic structures is associated with a drastic change of the exchange interactions between Fe-spins due to the introduction of oxygen.
|Journal||Applied Physics A: Materials Science and Processing|
|Publication status||Published - 2002 Dec 1|
ASJC Scopus subject areas
- Materials Science(all)