Ferromagnetism and metal-like transport in antiferromagnetic insulator heterostructures

Strained Pr$_{0.5}$Ca$_{0.5}$MnO$_3$/La$_{0.5}$Ca$_{0.5}$MnO$_3$/Pr$_{0.5}$Ca$_{0.5}$MnO $_3$ trilayers were grown on (001)-SrTiO$_3$ substrates using the pulsed-laser deposition technique. The coupling at the interfaces of several trilayers has been investigated from magnetization and electronic transport experiments. An increase of La$_{0.5}$Ca$_{0.5}$MnO$_3$ layer thickness induces a magnetic ordering in the strain layers and at the interfaces leading to ferromagnetic behavior and enhanced coercivity, while resistivity shows metal-like behaviors. These effects are not observed in the parent compounds, which are antiferromagnetic insulators, opening a path, to induce artificially some novel properties.