ANTIFERROMAGNETIC METALLIC STATE IN THE HEAVILY-DOPED REGION OF PEROVSKITE MANGANITES

Comprehensive study on electronic and magnetic properties has been per formed for doped manganite near the phase boundary of the antiferromag netic metallic (AFM) state, with changing the nominal hole concentrati on x and the one-electron bandwidth W. In La1 - xSrxMnO3 with maximal W, the ferromagnetic metallic ground state in the low-x region is repl aced by the AFM state beyond x = 0.54. On the other hand, the charge-o rdered insulating (COI) state appears at x similar to 0.5 for Nd1 - xS rxMnOx with reduced W. The COI ground state is overwhelmed by the AFM state with further increasing x (greater than or equal to 0.54) or W. These competitions of the AFM state with the alternative ground states suggest that the AEM state is a fundamental ground state for doped ma nganites.