• Magnetic coupling and magnetoresistance in ${\mathrm{La}}_{\text{0.55}}{\mathrm{Sr}}_{\text{0.45}}{\mathrm{MnO}}_3/$ ${\mathrm{La}}_{\text{0.67}}{\mathrm{Ca}}_{\text{0.33}}$ ${\mathrm{MnO}}_3$ multilayers

We have studied the interlayer coupling and the magnetoresistant effect of ${\mathrm{La}}_{\text{0.55}}{\mathrm{Sr}}_{\text{0.45}}{\mathrm{MnO}}_3/$ ${\mathrm{La}}_{\text{0.67}}{\mathrm{Ca}}_{\text{0.33}}{\mathrm{MnO}}_3$ structures. Magnetization loops, measured in ${\mathrm{La}}_{\text{0.55}}{\mathrm{Sr}}_{\text{0.45}}{\mathrm{MnO}}_3/{\mathrm{La}}_{\text{0.67}}{\mathrm{Ca}}_{\text{0.33}}{\mathrm{MnO}}_3/{\mathrm{La}}_{\text{0.55}}{\mathrm{Sr}}_{\text{0.45}}{\mathrm{MnO}}_3$ trilayers, indicate that there is a ferromagnetic coupling of the ${\mathrm{La}}_{\text{0.55}}{\mathrm{Sr}}_{\text{0.45}}{\mathrm{MnO}}_3$ layers across the ${\mathrm{La}}_{\text{0.67}}{\mathrm{Ca}}_{\text{0.33}}{\mathrm{MnO}}_3$ spacer up to room temperature, even above the Curie temperature of the ${\mathrm{La}}_{\text{0.67}}{\mathrm{Ca}}_{\text{0.33}}{\mathrm{MnO}}_3$ layers. However, magnetization versus temperature curves present signatures of the magnetic ordering of both compounds. No extrinsic magnetoresistance associated with the multilayered structure was observed in the whole temperature range due to the presence of the interlayer ferromagnetic coupling.