Samarium doped Ni-Zn ferrites (Ni0.5Zn0.5SmxFe2-xO4) were synthesized using sol-gel auto-combustion technique with Sm3+ doping concentrations varying as x = 0.00, 0.05, 0.10, 0.15, and 0.20. The prepared nanomaterials were examined using X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), complex impedance spectroscopy (CIS) and vibrating sample magnetometer (VSM). The XRD examination verified the pure FCC spinel phase of all samples with no impurity peak. The FTIR analysis for spinel molecules formation identified two frequency bands at the octa and tetrahedral sites. The TEM analysis confirmed the shape, size and distribution of prepared nanoparticles. The different dielectric properties were analyzed with a frequency range of 1 MHz to 3 GHz and the impact of doping was also studied simultaneously. Magnetic nature of prepared materials was investigated at room using the VSM. It is found that the prepared nanomaterials are suitable for high energy storage as well as magnetic applications.