Structural and electromagnetic properties of Ni–Zn ferrites prepared by sol–gel combustion method

Ni–Zn ferrite nanoparticles with composition of Ni1−xZnxFe2O4 (where x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by the chemical sol–gel combustion method at low temperature with a final pH value of 7. The synthesized nanopowder can be densified at a temperature lower than 950 °C. X-ray diffraction results showed that the dried gels synthesized from metal nitrates and citric acid transformed directly into nano-sized ferrite particles after a combustion process in air. The Zn content has a significant influence on the electromagnetic properties such as dielectric constant (ɛ′), dielectric loss tangent (tan δ) and complex dielectric constant (ɛ″). These values decrease with increasing of zinc. It is also shown that Ni–Zn powder exhibited saturation magnetization 73 emu g−1 at 950 °C.