Synthesis and investigation of the V2O5 effect on the properties of Na2O–NiO-(1-x)P2O5–xV2O5 (0≤x≤0.6) system

Abstract

This study reports on the properties of glasses and glass-ceramics isolated in a novel ternary system Na2O–NiO-(1-x)P2O5–xV2O5 with varying concentrations of V2O5 (x = 0, 0.2, 0.4, and 0.6 mol%). The materials were prepared by melting the mixture of reagents with stoichiometric proportions. Their amorphous and crystalline nature was confirmed via the XRD analysis. The vitreous feature and thermal parameters of the glasses were explored using differential scanning calorimetry. The density values have shown an increase and a slight decrease in the molar volume with the increase in the V2O5 content. The elemental composition of the glass and glass-ceramics was studied using energy-dispersive X-ray spectroscopy. In addition, the study examined the influence of the composition on the structure of the materials using both IR and Raman spectroscopies. XRD analysis of annealed samples revealed the presence of different crystalline phases depending on the V2O5 content. The EPR results were influenced by the variation of concentration of V2O5 and indicated the presence of V4+ ions in octahedral sites with tetragonal compression. The analysis of the magnetization according to the magnetic field at different temperatures showed a ferromagnetic behavior at low temperatures and a paramagnetic one at higher temperatures for all glasses. Magnetic susceptibility data reveal a Curie-Weiss behavior and the predominance of antiferromagnetic interactions. The dielectric studies were conducted as a function of temperature and frequencies to evaluate the composition effect on the dielectric constant, dielectric loss, and ionic conductivity. Electrical features were also examined using impedance spectroscopy.