Modeling of colossal magnetoresistance in La0.67Ca0.33MnO3/Pr0.67Ca0.33MnO3 superlattices: Comparison with individual (La1−yPry)0.67Ca0.33MnO3 films

Colossal magnetoresistance (CMR) and nm-scale electronic inhomogeneity close to the first order phase transition in perovskite manganites, e.g., (La1−yPry)0.67Ca0.33MnO3 still remain a puzzling phenomenon. We experimentally model a metal-insulator phase coexistence by growing a short period (LCMOn/PCMOn)m superlattices (SLs) with the same thickness for both components. CMR effect was studied as a function of the individual layer thickness n = 2–8 and then compared with chemically homogeneous (La1−yPry)0.67Ca0.33MnO3 LPCMO films. We show that SLs can be superimposed in the phase diagram of LPCMO. The results also point out the importance of the nm-scale electronic rather than chemical separation for realization of the CMR effect as well as limits the lowest boundary for the thickness of an individual manganite material to n∼4u.c.