LOCAL JAHN-TELLER DISTORTION IN LA1-XSRXMNO3 OBSERVED BY PULSED-NEUTRON DIFFRACTION

The atomic pair-density function of La1-xSrxMnO3 (0 less than or equal to x less than or equal to 0.4) obtained by pulsed neutron diffractio n indicates that their local atomic structure significantly deviates f rom the average structure, and that the local Jahn-Teller (JT) distort ion persists even when the crystallographic structure shows no JT dist ortion. In the paramagnetic insulating phase doped holes form one-site small polarons, represented by the local absence of JT distortion. Th e polarons become more extended at low temperatures, but local distort ions are found even in the metallic phase. The role of polarons in the phase transitions in transport and magnetic properties are discussed.