Abstract: Layered perovskite LaSr₂Mn_2-xCu_xO₇ polycrystalline samples were prepared by solid state reaction. Structure and magnetic as well as electric properties were nvestigated
by X-ray diffraction, superconductor quantum interference device and direct current four probe method. The samples have the single phase with layered perovskite structure and the space group is I4/mmm. The substitution of 10％ copper destroys the charge order of LaSr₂Mn₂O₇. Characteristic spin glass state occurs on the LaSr₂Mn_xCu_xO₇, and the spin frozen temperature is near 225K. The electric properties show that the LaSr₂Mn₂O₇ sample’s conduction characters are influenced by the substitution of 10％ Cu, which keeps in the insulator state from 77K to room temperature. At the same time, transport properties are changed by the substitution of 10％ copper. layered perovskite; LaSr₂Mn _2-x Cu_xO₇; magnetic properties; electrical properties

Key words: layered perovskite, LaSr₂Mn_2-x Cu_xO₇, magnetic properties, electrical properties