INFLUENCE OF CHROMIUM SUBSTITUTION ON THE STRUCTURAL AND ELECTRICAL PROPERTIES OF MAGNESIUM TITANIUM PHOSPHATE CERAMIC ELECTROLYTES PREPARED VIA SOL-GEL METHOD
Abstract
Magnesium-based electrolytes have gained significant popularity recently among researchers as an environmentally friendly alternative to lithium electrolytes. In this study, Magnesium Titanium Phosphate with the substitution of Chromium, Mg0.5+x/2CrxTi2-x(PO4)3 ceramic electrolytes were synthesized using the sol-gel method, with various x values. The impact of these x values of 0.1, 0.3, 0.5, 0.7, and 0.9 on the structural and electrical properties of the Mg0.5+x/2CrxTi2-x(PO4)3 samples was then investigated. X-ray Diffraction analysis revealed that the samples exhibited a hexagonal-shaped NASICON-type structure with R3c symmetry and some minor unidentified impurities across x values of 0.1, 0.3, 0.5, 0.7, and 0.9. Additionally, Fourier Transform Infrared analysis showed that the dominant vibrations in the samples came from the PO4 tetrahedra. Microstructural analysis shows that increasing the Chromium content from 0.1 to 0.9 progressively refines the grain structure, resulting in smaller and more homogeneous grains. The electrical properties were then evaluated using Electrochemical Impedance Spectroscopy, revealing that the highest bulk conductivity of the samples occurred at x = 0.9 (8.97 x 10-8 S.cm-1), while the highest grain boundary conductivity of the samples was observed at x = 0.1 (4.66 x 10-9 S.cm-1). The greatest total conductivity of the samples was achieved at x = 0.1 with a value of 4.42 x 10-9 S.cm-1. Overall, the findings suggest that varying the x value significantly influences the structural and electrical properties of the Mg0.5+x/2CrxTi2-x(PO4)3 ceramic electrolytes.
