Temperature-Dependent Magnetic Response of Antiferromagnetic Doping in Cobalt

Abstract: In this work Mn x Co 1 x Fe 2 O 4 nanoparticles (NPs) were synthesized using a chemicalco-precipitation method. Phase purity and structural analyses of synthesized NPs were performed byX-ray diffractometer (XRD). Transmission electron microscopy (TEM) reveals the presence of highlycrystalline and narrowly-dispersed NPs with average diameter of 14 nm. The Fourier transforminfrared (FTIR) spectrum was measured in the range of 400–4000 cm 1 which confirmed the formationof vibrational frequency bands associated with the entire spinel structure. Temperature-dependentmagnetic properties in anti-ferromagnet (AFM) and ferromagnet (FM) structure were investigatedwith the aid of a physical property measurement system (PPMS). It was observed that magneticinteractions between the AFM (Mn) and FM (CoFe 2 O 4 ) material arise below the Neel temperatureof the dopant. Furthermore, hysteresis response was clearly pronounced for the enhancement inmagnetic parameters by varying temperature towards absolute zero. It is shown that magneticproperties have been tuned as a function of temperature and an externally-applied field.