Symmetry analysis of the magnetic structures of bilayered manganites La2-2xSr1-2xMn2O7 near x=0.3: Phase separations and percolation

Article

关键词: INTERPLANE TUNNELING MAGNETORESISTANCE;    PEROVSKITE LA2-2XSR1+2XMN2O7 X=0.40;    NEUTRON-DIFFRACTION;    ORDERING PROCESS;    COLOSSAL MAGNETORESISTANCE;    GIANT MAGNETORESISTANCE;    T-C;    LA1.2SR1.8MN2O7;    LA1.4SR1.6MN2O7;    TRANSITIONS;   

DOI  :  10.1103/PhysRevB.62.5297

来源: SCIE

【 摘 要 】

We analyze the symmetry of the magnetic structures of tetragonal bilayered manganites La2-2xSr1+2xMn2O7 with doping near x=0.3 and formulate a corresponding Landau theory of the phase transitions involved. It is shown that a phase with a single magnetic order cannot be canting though with a mixture of different magnetic orders can, as is possibly the case near x=0.4. Accordingly, a schematic magnetic phase diagram near x=0.3 is constructed which may consistently account for the controversial experimental observations. Possible phase separations and a percolation mechanism of the colossal magnetoresistance no discussed.

【 授权许可】

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