Spin dynamics investigation and structural analysis of ambient scalable Sr2+ doped zirconium ferrite nanoparticles synthesized by low temperature auto combustion route.

Microwave spin resonance behaviour of Sr2+ doped Zirconium ferrite Zr 1-x Sr x Fe 2 O 4 ; (0 ≤ x ≥ 0.20) nanoparticles synthesized by auto combustion route has been investigated by electron paramagnetic resonance (EPR) which show a broad ferromagnetic resonance signal with a superimposed hump signal which is attributed to ferrite Fe3+ ions and oxygen vacancies which is in agreement with XRD and XPS. EPR shows low spin concentration and smaller relaxation time for Zr 0.80 Sr 0.20 Fe 2 O 4 which can be used for hyperthermia and for use as a MRI contrast agent. EDS and XPS confirms the presence of Zr, Sr, Fe, O, and C and HRTEM images confirm growth along (220) and (311) with an interatomic distance of 0.3327 nm and 0.2622 nm respectively, thus, authenticating the formation of spinel structure in agreement with FTIR studies. The magnetic behaviour (M − H loop) shows high saturation magnetization and higher value of effective magnetocrystalline anisotropy (K e f f) for Zr 0.80 Sr 0.20 Fe 2 O 4. [Display omitted] [ABSTRACT FROM AUTHOR]