Effect of ferromagnetic/antiferromagnetic interfaces on the magnetic properties of La2/3Sr1/3MnO3/Pr2/3Ca1/3MnO3 superlattices

The magnetic properties of a series of ferromagnetic/antiferromagnetic (FM/AFM) superlattices are studied. The multilayers are composed of five La2/3Sr1/3MnO3/Pr2/3Ca1/3MnO3 (LSMO/PCMO) bilayers, grown by pulsed laser deposition using SrTiO3 as the substrate. The evolution of the magnetic moment with the AFM PCMO layer thickness (0 <= t(A)<= 7.6 nm) is analyzed and is found to be strongly affected by the strain fields introduced by the FM/AFM interfaces. The effect on the LSMO is the appearance of a magnetic dead layer of similar to 1.5 nm, close to the interface with the PCMO. On the contrary, the magnetic moment of PCMO is remarkably enhanced for thicknesses t(A) around 3.5 nm, where nanometric FM droplets would find the optimal strain conditions to be accommodated within the AFM PCMO spacer. The implications of these findings on the magnetoresistance response are discussed. (C) 2006 American Institute of Physics.