Magnetic and Photoluminescent Coupling in SrTi_0.87Fe_0.13O_3−δ/ZnO Vertical Nanocomposite Films

Self-assembled growth of SrTi_0.87Fe_0.13O_3−δ (STF)/ZnO vertical nanocomposite films by combinatorial pulsed laser deposition is described. The nanocomposite films form vertically aligned columnar epitaxial nanostructures on SrTiO₃ substrates, in which the STF shows room-temperature magnetism. The magnetic properties are discussed in terms of strain states, oxygen vacancies, and microstructures. The nanocomposites exhibit magneto-photoluminescent coupling behavior that the near-band-edge emission of ZnO is shifted as a function of magnetic field

Hierarchical Templating of a BiFeO₃–CoFe₂O₄ Multiferroic Nanocomposite by a Triblock Terpolymer Film

A process route to fabricate templated BiFeO₃/CoFe₂O₄ (BFO/CFO) vertical nanocomposites is presented in which the self-assembly of the BFO/CFO is guided using a self-assembled triblock terpolymer. A linear triblock terpolymer was selected instead of a diblock copolymer in order to produce a square-symmetry template, which had a period of 44 nm. The triblock terpolymer pattern was transferred to a (001) Nb:SrTiO₃ substrate to produce pits that formed preferential sites for the nucleation of CFO crystals, in contrast to the BFO, which wetted the flat regions of the substrate. The crystallographic orientation and magnetic properties of the templated BFO/CFO were characterized