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

Abstract

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. IMPACT STATEMENT The BWO:CFO VAN thin film combining a ferroelectric layered oxide matrix and magnetic vertical nanocone present a new hybrid material platform for room temperature multiferroics design towards nanoscale sensors and actuators.

Tunable physical properties in Bi-based layered supercell multiferroics embedded with Au nanoparticles

“…, systems with ferromagnetic and ferroelectric coupling, and systems with magneto-optical coupling. 12,15,23–26 In general, three types of nanocomposite morphologies have been successfully fabricated using pulsed laser deposition (PLD), i.e. , particle-in-matrix (PIM) structure, multilayer structure, and vertically aligned nanocomposite (VAN) structure.…”

Preferentially Oriented Nanometer-Sized CoFe2O4 Mesocrystals Embedded in the BiFeO3 Matrix for Opto-Magnetic Device Applications

“…15−17 In particular, when the CFO mesocrystals are embedded in a matrix to form a specifically designed nanocomposite system, it not only provides a way of controlling the formation of CFO mesocrystals but also enables the engineering of couplings between the CFO mesocrystals and the host matrix, which in turn is a key ingredient for developing next-generation electronic devices with emergent functionalities. 15−23 In fact, a long list of examples have been successfully demonstrated along this line, including well-known multiferroicity in vertically aligned nanocomposites of the CFO-BiFeO 3 (BFO) matrix and CFO-BaTiO 3 matrix, 23−25 a light-induced ultrafast magnetization change in the CFO-SrRuO 3 matrix, 18 large magnetic anisotropy in the multiferroic CFO-Bi 2 WO 6 matrix, 26 an ultralow leakage current in the multiferroic CFO-Na 0.5 Bi 0.5 TiO 3 matrix, 27 a multiferroic nanocomposite of the CFO-PbTiO 3 matrix, 16,28 a transparent magnetic nanocomposite of the CFO-SrTiO 3 matrix, 16 magnetic-assisted magnetoresistance of the CFO-La 0.7 Sr 0.3 MnO 3 matrix, 29 and so forth. Among them, the BFO-CFO heteroepitaxy having the 1−3 architecture containing pillar-like CFO mesocrystals embedded in a BFO matrix is a well-known multiferroic composite with strong magnetoelectric coupling due to the smaller substrate clamping effect and higher interface-to-volume ratio interactions of BFO-CFO, unlike its 2-2 and 0-3 counterparts.…”

“…Alternatively, the CFO could also be fabricated in the form of mesocrystals embedded in a matrix with interesting properties to give rise to emergent functionalities. − In general, the CFO mesocrystals can be regarded as a collective system comprising nanosized CFO grains having the same crystallographic orientation with percolated connectivity. Such unique microstructure often leads to unprecedented properties vastly different from those observed in bulk or single-crystalline thin films and randomly oriented nanocrystals. − In particular, when the CFO mesocrystals are embedded in a matrix to form a specifically designed nanocomposite system, it not only provides a way of controlling the formation of CFO mesocrystals but also enables the engineering of couplings between the CFO mesocrystals and the host matrix, which in turn is a key ingredient for developing next-generation electronic devices with emergent functionalities. − In fact, a long list of examples have been successfully demonstrated along this line, including well-known multiferroicity in vertically aligned nanocomposites of the CFO-BiFeO 3 (BFO) matrix and CFO-BaTiO 3 matrix, − a light-induced ultrafast magnetization change in the CFO-SrRuO 3 matrix, large magnetic anisotropy in the multiferroic CFO-Bi 2 WO 6 matrix, an ultralow leakage current in the multiferroic CFO-Na 0.5 Bi 0.5 TiO 3 matrix, a multiferroic nanocomposite of the CFO-PbTiO 3 matrix, , a transparent magnetic nanocomposite of the CFO-SrTiO 3 matrix, magnetic-assisted magnetoresistance of the CFO-La 0.7 Sr 0.3 MnO 3 matrix, and so forth.…”

Vertically aligned nanocomposite (BaTiO3)0.8 : (La0.7Sr0.3MnO3)0.2 thin films with anisotropic multifunctionalities

“…A similar approach has been applied for other VAN systems. [26][27][28] In this work, two deposition frequencies of 2 Hz and 10 Hz were utilized for tuning the microstructure of the lms, i.e. thinner pillars can be obtained by increasing the deposition frequency.…”