Nb2O5-doped NiZnCo ferrite ceramics with ultra-high magnetic quality factor and low coercivity for high-frequency electronic devices

This work investigates the influence of niobium pentoxide (Nb 2 O 5 ) as dopant , on the structural, magnetic, and dielectric properties of NiZnCo ferrites. The results showed that Nb 2 O 5 was an effective dopant, and the Nb 5+ ions entered the B site to replace Fe 3+ ions, which altered the electromagnetic properties of the NiZnCo ferrite. In particular, the coercivity ( H c ) was 20∼24 Oe, and the magnetic quality factor ( Q ), was more than 200 at x = 0 and x = 0.1 wt%, which is 4∼5 times higher than that of NiZn and NiCuZn ferrites. Excellent electromagnetic properties were obtained for 0.1 wt% Nb 2 O 5 -doped NiZnCo ferrite, i.e. , M s = 88.3 emu/g, H c =20.4 Oe, ρ = 2.4 × 10 5 Ω m and Q = 202 @20 MHz. These excellent electromagnetic properties of Nb 2 O 5 -doped NiZnCo ferrites could be potentially applied to resonators and capacitors at high frequency.