Multiferroic vertically aligned nanocomposite with CoFe2O4 nanocones embedded in layered Bi2WO6 matrix

摘要

Bi_(2)WO_(6):CoFe_(2)O_(4) (BWO:CFO) vertically aligned nanocomposite (VAN) in epitaxial thin film form has been demonstrated on single-crystal LaAlO_(3) (LAO) (001) substrates via pulsed laser deposition (PLD). CFO nanopillars exhibit a unique nanocone shape embedded in the epitaxial BWO matrix with an Aurivillius layered oxide structure. The growth direction of the CFO nanopillars is (004), different from that of its epitaxial single-phase counterpart (220), which is attributed to the interfacial strain effect. Magnetic measurements show robust and anisotropic magnetic properties from the CFO nanocone structures, and obvious ferroelectric responses are demonstrated in the BWO matrix, both at room temperature.