| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1445690 | Acta Materialia | 2014 | 8 Pages |
We report on a detail study of the structural, magnetic and magnetocaloric properties of Zn-doped nickel–zinc ferrites with different Zn concentrations. Polycrystalline Ni1−xZnxFe2O4 (0.0 ⩽ x ⩽ 0.7) ferrite samples were prepared using the conventional solid-state reaction method. The X-ray diffraction results indicate that the ferrite samples have a cubic spinel type structure without any impurity phase. Temperature-dependent magnetization measurements and Arrott analysis reveal second-order ferromagnetic transition in all samples, with the Curie temperature decreasing progressively with increasing Zn concentration, from ∼845 K for x = 0.0 to 302 K for x = 0.7. An increase in magnetization at low temperature was observed for Zn doping up to x = 0.5. A maximum in magnetic entropy change, |ΔSMmax| (∼1.39 J kg−1 K−1 at 2.5 T), was observed in the Ni0.7Zn0.3Fe2O4 sample. The width of magnetic entropy curve was found to increase with the Zn concentration. Also, the |ΔSMmax| and relative cooling power were found to increase with increasing applied magnetic field, which indicates much greater cooling power is expected with a larger magnetic field. This investigation suggests that Ni1−xZnxFe2O4 (0.0 ⩽ x ⩽ 0.7) ferrite samples are possible candidates for magnetic refrigeration across a wide range of working temperatures.
Graphical abstractIsothermal magnetic entropy change for Ni1−xZnxFe2O4 samples at different temperatures under the applied magnetic field up to 2.5 T. We report detail study on the structural, magnetic, and magnetocaloric properties of Zn doped nickel–zinc ferrites with different Zn-concentrations. A maximum in magnetic entropy change, |ΔSMmax| (∼1.39 J kg−1 K−1 at 2.5 T) has been observed in Ni0.7Zn0.3Fe2O4 sample. The width of magnetic entropy curve was found to increase with the Zn concentration. Also, the |ΔSMmax| and relative cooling power were found to increase with increasing the applied magnetic field, which indicates much larger cooling power to expected at higher magnetic field. This investigation suggests that Ni1−xZnxFe2O4 (0.0 ⩽ x ⩽ 0.7) ferrite samples can be a possible candidate for magnetic refrigerating material with wide range of temperature.Figure optionsDownload full-size imageDownload high-quality image (119 K)Download as PowerPoint slide
