E r 3+ -doped Na-Al-K-Ba phosphate glasses were prepared by conventional melt quenching technique.The structure was studied using XRD and it showed that all the samples were in amorphous form.Physical properties such as density and refractive index have been measured.While the dielectric studies were carried out using (KEYSIGHT-E4991B) over a wide range of frequency extending from 1 MHz up to 1GHz...