Synthesis, structural characterization and magnetic properties of ordered mesoporous Pr1−xCaxMnO3 thin films

Abstract

Mixed-valence manganese oxides with a perovskite structure are promising candidates for next-generation electronic devices, among others, because of the combination of ferromagnetism with other technologically important properties. Herein we report the block copolymer-templating synthesis, structural characterization and magnetic properties of thermally stable thin films of cubic mesoporous praseodymium calcium manganite (PCMO), Pr_1−xCa_xMnO₃ with x ≈ 0.3. This novel sol–gel derived material is one of the rare examples of a complex mixed-metal oxide with both uniform and ordered nanoscale porosity. Calcination in air at 750 °C produces the desired crystallinity without compromising the pore-solid architecture. The data acquired from superconductive quantum interference device magnetometry confirm the phase purity and high degree of crystallinity. Below around 115 K, the films show clear signs of ferromagnetic behavior, with large low-temperature coercivity. Collectively, the results unequivocally demonstrate the quality of the polymer-templated mesostructured PCMO thin films, whose unique morphology makes them attractive for a variety of applications and further provides an opportunity for designing tailored and multifunctional (host/guest) nanocomposites.