Low-temperature MFM studies of CMR manganites

We have performed low-temperature Magnetic Force Microscopy (MFM) studies o f colossal magneto-resistive (CMR) (La0.67Ca0.33)MnO3 films prepared by phy sical vapor codeposition (PVCD). The samples exhibit sharp metal-insulator transitions at T-c = 265 K, and 120 nm grain structures. MFM studies perfor med down to T = 77 K showed irregularly-shaped magnetic features at tempera tures below T-c. Characteristic magnetic domain sizes were 1-2 mum, which e xceeds the grain size for these films, implying coherence across grain boun daries in this system.