Substitutional effect of copper on the cation distribution in cobalt chromium ferrites and their structural and magnetic properties

Abstract

A series of copper substituted cobalt chromium ferrites, Cu x Co 1 − x Cr 0.5 Fe 1.5 O 4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) has been synthesized, by employing powder metallurgy method. Calcination of the samples has been carried out for 24 hours at 1100°C. The resultant materials have been investigated by using a variety of techniques, including X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM)), scanning electron microscopy (SEM), and ultraviolet visible spectroscopy (UV-Vis). The XRD patterns confirmed that all compositions had a cubic spinel structure with a single phase and the lattice parameter was found to increase with increasing copper concentration. FT-IR spectroscopy has been used for studying the chemical bonds in the spinel ferrite. Shifting of the bands υ 1 and υ 2 has been observed. It has been revealed from VSM analysis that saturation magnetization and coercivity decrease with rising the Cu +2 doping. Magnetic properties have been explained on the basis of cation distribution. Scanning electron microscopy (SEM) has been used to study the surface morphology of prepared samples. UV-Vis analysis revealed the optical absorption of the samples. An increase in band gaps has been observed with increasing copper concentration in the sample.

Efficacy of surface-functionalized Mg1−xCoxFe2O4 (0 ≤ x ≤ 1; Δx = 0.1) for hyperthermia and in vivo MR imaging as a contrast agent

“…However, F CT decreases and F CO increases with increasing cobalt content x , which indicates that the orbital overlap at the A-site decreases and that at the B-site increases with x , i.e. , Co concentration 46 because of the preferance of Co at the B-site.…”

“…The fact that the areas of the subspectra representing the sextet decrease with the decrease in cobalt (Table 1) because of the ferrimagnetic to superparamagnetic transition, which corroborates with the results obtained from the physical property measurement system (PPMS) presented later. 40,41,44–46…”

Sol–Gel Auto-combustion Preparation of M2+ = Mg2+, Mn2+, Cd2+ Substituted M0.25Ni0.15Cu0.25Co0.35Fe2O4 Ferrites and Their Characterizations

“…LA is the distance between cation and oxygen ion at tetrahedral site while LB is the distance between cation and oxygen ion at octahedral site. The calculated values of LA and LB are reported in Fe 2+/3+ ions prefer both A-site (tetrahedral) and B-site (octahedral) while Cd 2+ ions prefer only tetrahedral sites [32][33][34][35][36]. The cation distribution of the as-prepared ferrites is determined by where, r(Cd 2+ ), r(Ni 2+ ), r(Cu 2+ ), r(Co 2+ ) and r(Fe 2+ ) are the ionic radii while CCd, CNi, CCu, CCo and CFer are the concentration of Cd 2+ , Ni 2+ , Cu 2+ , Co 2+ and Fe 3+ respectively.…”

Adsorption and gas sensing properties of CuFe2O4 nanoparticles

“…Spinel ferrites are defined as metal-ferrites with the general composition of MFe 2 O 4 , where M=Ni, Cu, Cd, Zn, etc. [1,2]. They exhibit semiconducting properties since they are metal-oxide materials [3].…”