Tuning the Structural and Magnetic Properties of the Stuffed Framework Structures MeFe2O4 (Me = Ni, Ca, and Sr)
Ebtesam E. Ateia, Sara Hussien, Amira T. Mohamed
Abstract
Abstract Spinel ferrite nanoparticles (NPs), have received a lot of attention in medical applications. Therefore, facile synthesis of ferrite NPs of numerous shapes and sizes using the citrate autocombustion technique was utilized in this article. A series of ferrite with the general formula MeFe 2 O 4 [Me = nickle (Ni), calcium (Ca), and strontium (Sr)] are synthesized with varying average ionic radii and cation disorder on the A-site. The structural and morphological characterization of the prepared samples was performed using XRD, HRTEM, FESEM, EDAX, XPS, and Raman analyses. The phase transformation from cubic (Ni) to orthorhombic (Ca) to monoclinic (Sr) was also revealed by XRD. Accordingly, HRTEM images demonstrated nanoparticles in orthorhombic and monoclinic shapes, which are inconsistent with XRD analyses. The coercive field H C for monoclinic SrFe 2 O 4 is ≈ 42 times larger than the H c for NiFe 2 O 4 with a cubic structure. This deviation in H C compared to the cubic shape particles can be coupled to the shape anisotropy present in SrFe 2 O 4 and refers to the presence of a preferred magnetization direction within the material. The use of monoclinic SrFe 2 O 4 NPs as antifungal activity agents is noteworthy due to their advantages in terms of surface area, efficacy, and biodegradability.