Different phosphor colors of SrAlxOy: Eu 0.01 2+ , R 0.01 3+ (R = Er3+, Tm3+ and Tb3+) nanopowders and pellets have been synthesized via citrate combustion technique. XRD results revealed that monoclinic SrAl2O4 was the major phase and hexagonal SrAl12O19 was the minor phase. Meanwhile, Field emission SEM images showed hollow cylindrical-like shape structures filled with the large number of nanorods for the SrAlxOy: Eu 0.01 2+ , Tb 0.01 3+ sample. The values of measured band gap energy and calculated refractive index were mainly dependant on the ionic radius of R3+ co-doping ion. The PL emission spectra and afterglow properties were strongly affected by the lanthanide type (R3+). For instance, Eu2+-SrAlxOy sample achieved the maximum dielectric permittivity (έ) ~16.77 and dielectric loss (tanδ) ~0.19 at the microwave frequency region (1 GHz). Meanwhile, Tb3+, Eu2+-SrAlxOy sample was possessed the minimum dielectric permittivity (έ) ~1.36 and dielectric loss (tanδ) ~0.0002 at the radiowave frequency region (100 MHz).