Crystal and magnetic structures and properties of BiMnO
BiMnOの構造,磁気構造及び物性
Belik, A. A.*; 樹神 克明 ; 井川 直樹 ; 社本 真一 ; 小須田 幸助*; 室町 英治*
Belik, A. A.*; Kodama, Katsuaki; Igawa, Naoki; Shamoto, Shinichi; Kosuda, Kosuke*; Muromachi, Eiji*
Crystal and magnetic structures of BiMnO (=0.03, 0.08, and 0.14) have been determined by the Rietveld method from neutron diffraction data at 8-10 and 290 K. BiMnO crystallizes in a monoclinic system with space group . BiMnO crystallizes in space group . It was found that Mn vacancies are localized mainly in one Mn site (among three sites) in BiMnO (=BiMnO). Vacancy-ordering and charge-ordering scenarios are suggested as possible reasons for the crystal symmetry change compared with BiMnO (=BiMnO). BiMnO and BiMnO are ferromagnetic below T = 82 and 68 K, respectively, with magnetic moments along the monoclinic b axes. Refined magnetic moments at 10 K are 2.88(2) in BiMnO and 2.33(2) in BiMnO. BiMnO crystallizes in an orthorhombic system with space group , and its structure is similar to that of LaMnO-LaMnO. No magnetic reflections were found in BiMnO down to 8 K, in agreement with its spin-glass magnetic state. Magnetic and chemical properties of BiMnO () have also been investigated and compared with those of LaMnO. Systematic changes of magnetic parameters in BiMnO were found to depend on .