Discussions on the film design and mechanical properties of Y³⁺/PVA polymeric composite films: enhancement of the electrical conductivity and dielectric properties

This paper focuses on the impact of yttrium nitrate salt (Y³⁺ ions) on the microstructural, mechanical, optical, and dielectric characteristics of poly(vinyl alcohol) (PVA) films. Simple solution casting technique was used to synthesize yttrium nitrate salt-doped PVA of different weight percent. These films are characterized using various methods such as differential scanning calorimetry, X-ray diffraction, stress–strain, UV–visible spectroscopy, and dielectric measurements. The thermal study reveals the reduction in the glass transition temperature T_g by a rise of Y³⁺ ions in the PVA matrix. The degree of crystallinity \({X}_{c}\) and X-ray diffraction results support the increase of the crystallinity of PVA due to the doping effect. The mechanical characteristics of PVA: Y³⁺ ions’ films like Young's modulus are reduced, but the percentage elongation at break is raised, by the increase of Y³⁺ ions content. UV–Vis spectroscopy has been used for the optical characteristics of the studied films, demonstrating the transmittance of UV–Vis films is decreasing with the rise of Y^{3 +} ions content in the composites. The bandgap E_g of Y³⁺/PVA films is significantly reduced with the addition of Y^{3 +} ions. The changes in optical characteristics of PVA are ascribed to the interaction of Y³⁺ ions with the PVA matrix. Also, the dielectric constant measurement of the studied polymeric composites examined and revealed a highly attractive dielectric constant for the dielectric media. With the increase in the incident frequency, both the dielectric constant and dielectric loss of the studied films is decreased exponentially. At the same time, the AC electrical conductivity is improved with increasing the Y³⁺ ions content. Y³⁺/PVA films have unique properties to be used in a different field such as electronic, optoelectronic, and device fabrication.