Structural, optical, elastic and magnetic properties of Ce and Dy doped cobalt ferrites

The CoCexDyxFe2-2xO4 (x = 0.0, 0.01, 0.02, 0.03, 0.04, 0.05) have been prepared by sol-gel auto-combustion technique. The structural result confirmed the formation of single phase cubic spinel structure showed by XRD. Crystallite size obtained from the XRD is in the range of 24-28 nm, whereas particle size obtained from the transmission electron microscopy is in the range of 20-30 nm. It is also found that the cation distribution of CoCexDyxFe2-2xO4 resulted in the Fe3+ and Co ions occupy both tetrahedral A-site and octahedral B-site, whereas Ce and Dy cation distributed in both of them. The photoluminescence (PL) analysis reveals that all prepared samples contain four bands; (i) peak centered at 412 nm corresponding to ultraviolet (UV) band i.e. near band edge emission, (ii) a high intensity peak centered at 434 nm belonging to violet band, (iii) a low intensity and sharpness peak positioned at 466 nm refers to blue band, and (iv) a broad and very low intensity peak observed at 502 nm assigned to green band. FTIR results of the prepared samples showed that two vibration bands between 600 cm(-1) and 400 cm(-1) belonging to the stretching vibration of tetrahedral metal-oxygen bond (v(A)) and stretching vibration of octahedral site (v(B)) respectively. Mossbauer spectroscopy has also been performed to investigate the hyperfine structure of undoped, Ce and Dy co-doped cobalt nano ferrites. The higher values of MS and H-hf for x = 0.01 composition can be attributed to the occupation of Dy3+ ions in octahedral site whereas the Ce3+ ions occupied to tetrahedral site. (c) 2020 Elsevier B.V. All rights reserved.