Room-temperature magnetocaloric effect in Fe-substituted CoCr2O4 spinels

Mg-Doped CoCr2O4 Nanoparticles: Implications for Magnetic Memory and Magnetocaloric Effect

“…The F 2g (3) peak position increases linearly as Mg concentration increases from 0 to 15 mol % and decreases from 15 to 20 mol % (Figure S5, Supporting Information). The F 2g (3) and F 2g (2) vibration bands shift toward the higher/lower-wavenumber side with an increase in Mg 2+ content due to the difference in ionic radii of Mg 2+ (0.72 Å) and Co 2+ (0.73 Å) ions . this F 2g (3) trends and E g vibration modes are consistent with the XRD and FE-SEM results, confirming Mg doping on the Co site in the CoCr 2 O 4 NPs.…”

“…The F 2g (3) and F 2g (2) vibration bands shift toward the higher/lower-wavenumber side with an increase in Mg 2+ content due to the difference in ionic radii of Mg 2+ (0.72 Å) and Co 2+ (0.73 Å) ions. 25 48 The T C and T S values decreased from 96 to 73 and from 20 to 12 K, respectively, as the Mg concentration increased from 0 to 20 mol %. The PM ordering above T C was confirmed by field-dependent magnetization (M−H).…”

“…To assess the suitability of our samples for magnetic refrigeration applications, we can utilize field-dependent isothermal magnetization curves to estimate the magnetic entropy change (−Δ S M ) induced by the magnetic field H , by employing the subsequent numerical approximation − normalΔ S normalM = prefix∫ 0 H max ( d M d T ) H d H …”

“…This MME phenomenon, triggered by a pulsed magnetic field, can be attributed to multiple magnetic state distributions characterized by different energy scales and interfacial exchange interactions between the FIM and AFM phases. Gulkesen et al 25 investigated the magnetocaloric effect in Fe-doped CoCr 2 O 4 NPs and reported a maximum (−ΔS M ) value of 0.88 J/kg•K for x = 0 (CoCr 2 O 4 ), while Kumar et al 26 studied the magnetocaloric effect for Co(Cr 0.95 Fe 0.05 ) 2 O 4 and found that the maximum relative cooling power (RCP) was 13 J/kg for Co(Cr 0.95 Fe 0.05 ) 2 O 4 .…”

Study of the spectroscopic, magnetic, and electrical behavior of PVDF/PEO blend incorporated with nickel ferrite (NiFe2O4) nanoparticles

“…Nickel ferrite (NiFe 2 O 4 ) has many applications for its high magnetic anisotropy, high saturation magnetization, and supermagnetic structure. NiFe 2 O 4 has a wide range of magnetic properties based on particle size and morphology, such as super magnetic behavior [1][2][3][4][5][6][7][8][9][10][11].…”