Preparation of lead hexaferrite filled PVA- PVP nanocomposite and a study of its structural features, optical and dielectric properties

Abstract

Abstract Polymer blend films based on PVA-PVP filled with PbFe 12 O 19 hexa-ferrites nanoparticles were created by solution casting technique. XRD, HRTEM, FESEM, FTIR, UV–vis spectroscopy and Broad-band dielectric spectroscopy were used to examine the properties of the prepared polymer composite films. X-ray diffraction pattern of the powder confirmed the formation of PbFe 12 O 19 with hexagonal phase and that for the films confirmed the incorporation of the PbFe 12 O 19 nanoparticles in the PVA-PVP blends. HRTEM confirms the formation of hexagonal nanoparticles with average size ranged from 7 nm to 21 nm. Field emission scanning electron microscopy (FESEM) studied the morphology of the nanocomposite films. There are noticeable variations in FT-IR spectra that confirm the incorporation of PbFe 12 O 19 , NPs in PVA-PVP blend. The absorbance was found to increase with red shift in the ultraviolet-visible region while the transmittance decreases with increasing PbFe 12 O 19 , nanoparticles. By incorporating, PbFe 12 O 19 the direct optical gap and indirect optical gap gradually decreased from 5.20 eV to 4.44 eV and 4.97 eV to 4.34 eV, respectively while the Urbach energy increases from 0.274 eV to 0.678 eV. According to the Wemple-Didomenico single oscillator model, the optical dispersion parameters have been examined and are found to be strongly affected by PbFe 12 O 19 , loading. Additionally, the nanocomposite film containing 7.5% PbFe 12 O 19 , demonstrated outstanding optical shielding. The complex dielectric constant ( ε* ), complex electric modulus (M * ) and electrical conductivity, of NCPs materials have been studied with the frequency changing from 0.1 Hz to 10 MHz. The real permittivity ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> <mml:mo accent="false">′</mml:mo> </mml:math> ) of PVA-PVP blend polymer film increased while the real electric modulus (M′) is found to decrease by the incorporation of PbFe 12 O 19 , nanoparticles up to 2.5 wt.% and the imaginary component of permittivity follows the same pattern of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> <mml:mo accent="false">′</mml:mo> <mml:mo>.</mml:mo> </mml:math> The examined nanocomposite films show promise for flexible optoelectronics, photosensors, optical shielding and nano-dielectric materials.