Sol–Gel Synthesis of Ce(4–x)Sr(1+x)Fe(5–x)Zn(x)O(14+δ) [0 ≤ x ≤ 0.45] Superparamagnetic Oxide Systems and Its Magnetic, Dielectric, and Drug Delivery Properties

[Image: see text] In this work, we have successfully synthesized superparamagnetic nanocomposites, Ce(4–x)Sr(1+x)Fe(5–x)Zn(x)O(14+δ) (0 ≤ x ≤ 0.45) (CSFZ) (TA1–TA4: x = 0, 0.15, 0.30, and 0.45) via the Nitrate–citrate sol–gel method. X-ray diffraction studies show the formation of single-phase nanocomposites (NCs) and the average crystallite size is found to be 18 nm. Energy-dispersive X-ray spectroscopy analysis supports the formation of the desired product with the expected composition. The scanning electron microscopy image shows that the prepared samples are in spherical shape and highly porous in nature. Most of the particle sizes present in the image are in the range of 5–20 nm. The optical studies show an intense peak at 583 nm corresponding to the instantaneous existence of both Fe(2+) and Fe(3+) intervalence electronic charge transition bands. X-ray photoelectron spectra analysis confirms the presence of elements with their preferred oxidation state. The superparamagnetic nature of the prepared sample was confirmed by vibrating sample magnetometer analysis. Synthesized materials show a low saturate magnetic moment ranging from 0.3400 to 0.1075 emu/g. The coercivity and retentivity value of the synthesized NC is zero. The NCs show high encapsulation efficiency toward ciprofloxacin hydrochloride because of their unique structure and release the loaded drug molecules in a sustained manner up to 10 h at pH 7.4. Such NCs have high potential for use as multifunctional material in various fields such as optical properties, conductivity studies, dielectric, sensor, and drug delivery properties.