Substrate effect on the magnetic microstructure of La0.7Sr0.3MnO3 thin films studied by magnetic force microscopy

Colossal magnetoresistive La0.7Sr0.3MnO3 thin films have been grown under t ensile strains on (100)-SrTiO3 substrates and compressive strains on (100)- LaAlO3 and (110)-NdGaO3 substrates by pulsed laser deposition. Using magnet ic force microscopy (MFM), a "feather-like" magnetic pattern, characteristi c of films with an in-plane magnetization, is observed for films deposited on both SrTiO3 and NdGaO3 while a "bubble" magnetic pattern, typical of fil ms with an out-of-plane magnetization, is recorded for LaAlO3. We show that the shape of the magnetic pattern imaged by MFM is fully correlated to the easy direction of the magnetization in the film. (C) 2001 American Institu te of Physics.