In this work, we report a novel approach to fabricate 0–3 type particulate nanocomposite thin films composed of dispersed CoFe2O4 (CFO) Belnacasan nanoparticles embedded in P(VDF-HFP) matrix. Prepared through spin/cast-coating techniques, such films exhibit homogenous thickness ranging
from 200 nm to 1.6 μm. With a focus on the potential for magnetoelectric coupling, the morphology, microstructure, dielectric, magnetic, and magnetoelectric properties selleck chemicals are investigated systematically. Methods The CoFe2O4 nanocrystals were synthesized by a hydrothermal route [21]. In a typical reaction, 2 mmol Co(NO3)2 · 6H2O (Aldrich, 98+%) and 4 mmol Fe(NO3)3 · 9H2O (Aldrich, 98+%) were first dissolved in deionized water. Ethanolamine was dropwise added in the solution until
precipitation completed. The obtained precipitate was collected by centrifugation and washed with deionized 10058-F4 nmr water. Ammonium hydroxide was then added to re-dissolve the solids. The reaction mixture was transferred into a stainless steel autoclave, with 80% volume filled with the ammonium hydroxide solution. The autoclave was then heated at 200°C for 10 to 30 h. The resultant CoFe2O4 nanopowders were washed, collected, and dried in air at 60°C overnight. The CoFe2O4/polymer nanostructured films were prepared via multiple spin coating and cast coating followed by thermal treatment. N,N-dimethylformamide was first used to dissolve CoFe2O4 nanoparticles and P(VDF-HFP) pallets or polyvinylpyrrolidone (PVP) powder separately, with concentration of 20 mg/ml. Then, the two suspensions were mixed under ultrasonification, according to the weight ratio of CFO versus polymer, and spin-coated or cast-coated on Si or glass substrates and dried at 90°C under vacuum. The thickness of the obtained thin films (200 nm to 1.6 μm) was controlled by the times and/or rotation learn more speed (300 to 1000 rpm) of the spin coating. To measure film thickness, scanning electron microscopy (SEM) cross-sectional analysis
was applied. The Si substrate was scored and cut/fractured in order to observe film cross sections, which were then easily analyzed by SEM. Correct instrumental calibration and review of the film over several regions confirmed thin film uniformity, expected for spin/cast coating, and thicknesses could be determined to within ±7%. For dielectric measurements, the glass substrates were pre-deposited with rectangular (1 mm × 5 mm) Ag bottom electrodes by a thermal evaporator. Top electrodes were deposited (5 mm × 1 mm) after the films were coated and dried, leaving the composite sandwiched between two electrodes with square crossed area of 1 mm × 1 mm. The phase purity and crystal structure of the CoFe2O4 particles was analyzed by X-ray diffraction (XRD) with a PANalytical powder X-ray diffractometer (Almelo, The Netherlands) with Ni-filtered Cu Kα radiation (λ = 1.54056 Å).