title: Magnetization reversal and microstructure in polycrystalline Fe50Pd50dot arrays by self-assembling of polystyrene nanospheres.
abstract: Nanoscale magnetic materials are the basis of emerging technologies to develop novel magnetoelectronic devices. Self-assembly of polystyrene nanospheres is here used to generate 2D hexagonal dot arrays on Fe50Pd50thin films. This simple technique allows a wide-area patterning of a magnetic thin film. The role of disorder on functional magnetic properties with respect to conventional lithographic techniques is studied. Structural and magnetic characteristics have been investigated in arrays having different geometry (i.e. dot diameters, inter-dot distances and thickness). The interplay among microstructure and magnetization reversal is discussed. Magnetic measurements reveal a vortex domain configuration in all as-prepared films. The original domain structure changes drastically upon thermal annealing performed to promote the transformation of disordered A1 phase into the ordered, tetragonal L10phase. First-order reversal magnetization curves have been measured to rule out the role of magnetic interaction among crystalline phases characterized by different magnetic coercivity.
authors.affiliation: Nanoscience and Materials Division, INRIM , Torino , Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Tiberto
authors.affiliation: Nanoscience and Materials Division, INRIM , Torino , Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Celegato
authors.affiliation: Nanoscience and Materials Division, INRIM , Torino , Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Barrera
authors.affiliation: Nanoscience and Materials Division, INRIM , Torino , Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Coisson
authors.affiliation: Nanoscience and Materials Division, INRIM , Torino , Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Vinai
authors.affiliation: Chemistry Department, Università di Torino , Torino , Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Rizzi
keywords: 101 Self-assembly / Self-organized materials; 106 Metallic materials; 203 Magnetics / Spintronics / Superconductors; 302 Crystallization / Heat treatment / Crystal growth; 40 Optical, magnetic and electronic device materials; 503 TEM, STEM, SEM; Self-assembling; magnetic thin film; magnetization reversal; microstructure; phase transformations