Simple synthesis and characterization of vertically aligned Ba_0.7Sr_0.3TiO₃–CoFe₂O₄multiferroic nanocomposites from CoFe₂nanopillar arrays

Abstract

A new strategy to elaborate (1-3) type multiferroic nanocomposites with controlled dimensions and vertical alignment is presented. The process involves a supported nanoporous alumina layer as a template for growth of free-standing and vertically aligned CoFe nanopillars using a room temperature pulsed electrodeposition process. BaSrTiO-CoFeO multiferroic nanocomposites were grown through direct deposition of BaSrTiO films by radio-frequency sputtering on the top surface of the pillar structure, with in situ simultaneous oxidation of CoFe nanopillars. The vertically aligned multiferroic nanocomposites were characterized using various techniques for their structural and physical properties. The large interfacial area between the ferrimagnetic and ferroelectric phases leads to a magnetoelectric voltage coefficient as large as ∼320 mV cm Oe at room temperature, reaching the highest values reported so far for vertically architectured nanocomposite systems. This simple method has great potential for large-scale synthesis of many other hybrid vertically aligned multiferroic heterostructures.

Strain-Induced Magnetoelectric Coupling in Fe3O4/BaTiO3 Nanopillar Composites

“…The 1–3-type multiferroic composites are vertically aligned heteroepitaxial structures, which have the advantages of the large interfacial area and the significantly reduced substrate clamping effect . Recently, various 1–3-type multiferroic composites has been explored, such as BiFeO 3 /CoFe 2 O 4 , BTO/CoFe 2 O 4 , BTO/La 0.7 Sr 0.3 MnO 3 , BTO/Fe, , BTO/Y 3 Fe 5 O 12 , and Ba 0.7 Sr 0.3 TiO 3 /CoFe 2 O 4 , which exhibit excellent ME coupling properties.…”

Magnetic Nanowires

“…Extensive studies were realized on many ferromagnetic NW arrays using various experimental techniques for a deeper understanding of the magnetic properties and spin-dependent transport properties in relation with their nanoscopic dimensions . The research activity at UCLouvain on magnetic NWs were also motivated by related applications in microwave devices [46][47][48][49][50][51][52][53][54] and multiferroic nanocomposites [55][56][57][58][59]. Recently, we demonstrated the suitability of three-dimensional (3D) nanoporous polymer templates to form dense interconnected magnetic NW networks with tunable geometrical parameters in terms of nanowire size, density, and orientation opens up the possibility for a controlled synthesis of a large variety of complex 3D networks of high aspect-ratio nanostructures with different geometries and materials [60][61][62][63][64][65][66][67].…”

Fabrication and physical properties of microrod-type multiferroic composite thin films by metal organic decomposition

“…1,2) Most MF composite films consist of laminated structures of ferroelectric layers such as Pb(Zr,Ti)O 3 (PZT), BaTiO 3 or bismuth-layered structure compounds (BLSFs) deposited on a ferromagnetic layer such as cobalt ferrite (CFO). [3][4][5][6][7][8][9][10][11] The goal is to obtain a large magnetoelectric (ME) effect 9,[11][12][13][14][15][16] and to develop electric-magnetic energy conversion devices by reducing the clamping effect of the substrate to the utmost limit. To achieve this, it is necessary to produce a template with a high aspect ratio by microfabricating the underlying thin film using reactive ion etching (RIE).…”