In this article, NiMn1-xFe2O4 ferrite nanoparticles were synthesized using surfactant free ultrasonic method, that x= 1, 0.75, 0.5, 0.25 and 0. The crystal structure of the synthesized nanoparticles was investigated using X-ray diffraction (XRD). It was found that they have a spinel structure. The crystallite size of the nanoparticles was also measured using Scherrer’s relation. The morphology of nanoparticles was studied using scanning electron microscope (SEM). The magnetic properties and hysteresis loop of NixMn1-xFe2O4 ferrites were investigated using vibrating sample magnetometer (VSM). The value of coercivity, saturation magnetization and remanent magnetization of the samples were calculated. In order to investigate the photocatalytic properties of the synthesized nanoparticles, the effect of particle on degradation of azo dyes acid brown and acid blue was studied. Based on the absorption spectrum obtained from the UVVis spectrometer, the amount of degradation of azo dyes by each of the nanoparticles were obtained at different times of UV irradiation.
