Microstructural analysis, magnetic properties, magnetocaloric effect, and critical behaviors of Ni_0.6Cd_0.2Cu_0.2Fe₂O₄ ferrites prepared using the sol–gel method under different sintering temperatures

Abstract

This work focuses on the microstructural analysis, magnetic properties, magnetocaloric effect, and critical exponents of Ni0.6Cd0.2Cu0.2Fe2O4 ferrites.

Autocombustion‐Promoted Synthesis of Lanthanum Iron Oxide: Application as Heterogeneous Catalyst for Synthesis of Piperidines, Substituted Amines and Light‐Assisted Degradations

“…This reason for such observation was the change in lattice parameters at higher calcination temperature. [60,61] Besides this, to get assured of the optimum calcination temperature necessary for the formation of the pure perovskite phase, the position of the diffraction peaks belonging to the calcination temperature 700°C were matched with ICSD Card no:-98-016-3226 ( Figure ES2) [62] The average crystalline size of the prepared NPs at various calcination temperatures was calculated by employing Debye-Schrrer's Equation. [63,64] where D denotes the mean size of the nanocrystallite (nm), K is the Schrrer's constant having the value 0.89, β is the width of the line at half maximum intensity (FWHM), λ is the wavelength of the X-ray used (0.1542 nm), Ɵ is the Bragg's angle (or angle of diffraction).…”

Magnetic properties, magnetocaloric effect, and critical behaviors in Co1−xCrxFe2O4

“…For x = 0.125, 0.250, and 0.375 it show the comparable values of RCP reported earlier for various ferrite materials. 4,29–32 From Table 3 , RCP values are found to increase with the increasing Cr content and found a maximum of 145 J kg −1 for x = 0.375 which is higher than the previously reported RCP values. 4,29–32 For x = 0.500 the RCP values are found to be very low which may be due to showing negative values of the vacancy parameter as explained in the previously reported article.…”

“… 4,29–32 From Table 3 , RCP values are found to increase with the increasing Cr content and found a maximum of 145 J kg −1 for x = 0.375 which is higher than the previously reported RCP values. 4,29–32 For x = 0.500 the RCP values are found to be very low which may be due to showing negative values of the vacancy parameter as explained in the previously reported article. 25 Another reason behind showing the lower values of RCP is non-universal behavior for x = 0.500.…”

“…The critical behavior has been conducted by measuring the magnetization isotherms (M–H) close to the respective T C following the procedure described in ref. 4 and 34 . The M–H isotherms for all samples are illustrated in Fig.…”

“…Relative Cooling Power (RCP) is another important criterion that helps to characterize the MCE of such magnetic materials. The RCP for all samples has been calculated using the following relation: 4 RCP = |Δ S max m | × δT FWHM where δT FWHM is the full width of the 0.5|Δ S max m |. The calculated RCP values are tabulated in Table 3 , where very lower values of RCP with lower |Δ S max m | for x = 0.00 are evident which may be due to the non-universal nature as explained in Section 3.3.…”