Hole-concentration-induced transformation of the magnetic and orbital structures in Nd1-xSrxMnO3

Article

关键词: METAL-INSULATOR-TRANSITION;    CHARGE-ORDERED STRIPES;    PEROVSKITE MANGANITES;    NEUTRON-DIFFRACTION;    MANGANESE OXIDES;    PHASE-DIAGRAM;    SPIN;    FIELD;    LA0.5CA0.5MNO3;    PR0.7CA0.3MNO3;   

DOI  :  10.1103/PhysRevB.60.9506

来源: SCIE

【 摘 要 】

We have peformed neutron diffraction measurements on melt-grown polycrystalline samples of Nd1-xSrxMnO3 (0.49 less than or equal to x less than or equal to 0.75). A systematic transformation of the crystalline and magnetic structures of this system was observed. This can be consistently explained by the change of the character of the Mn e(g) orbitals. When increasing x, the Nd1-xSrxMnO3 system exhibits an evolution from a metallic ferromagnetic state, to a metallic A-type antiferromagnetic (AFM), and then Co an insulating C-type AFM state. The CE-type charge-ordered AFM state was observed only in the vicinity of x = 1/2 and it coexists with the A-type AFM state for x greater than or similar to 1/2, indicating that the energy difference between these two states is very small. We also found that the MnO6 octahedra are apically compressed in the CE-type and A-type AEM states due to the d(3x(2)-r(2))/d(3y(2)-r(2)) or d(x(2)-y(2)) orbital ordering, whereas they are epically elongated by the rod-type d(3z(2)-r(2)) orbital ordering in the C-type AFM state. Finally, a selective broadening of Bragg peaks was observed in the C-type AFM phase and its nc dependence strongly suggests the onset of charge ordering for either x=4/5 or x=3/4. [S0163-1829(99)11737-5].

【 授权许可】

Free