Effect of Fe Substitution on the Physical Properties of La0.62Er0.05Ba0.33Mn1−xFexO3(x = 0.00, 0.05 and 0.15)

Abstract

Morphology, magnetic and magnetocaloric properties of La 0.62 Er 0.05 Ba 0.33 Mn 1−x Fe x O 3 (x = 0.00, 0.05 and 0.15) were experimentally investigated. Solid-state reaction method was used in the preparation of the samples. The microstructure of the samples was determined by scanning electron microscopy (SEM). From the XRD study, it has been found that all samples are single-phased and crystallized in the rhombohedral structure with the R3-c space group. For x = 0.05 and 0.15, a steep drop of zero field-cooled (ZFC) magnetization at low temperature signifies the formation of cluster-or spinglass state. This is caused by the competition between the ferromagnetic and antiferromagnetic interaction. A sensitive response to substituting Fe for Mn is observed in the magnetic and magnetocaloric properties. We found that Fe doping is powerful enough to reduce Curie temperature T C and it brings about cluster glass behaviours. The magnetocaloric effect is calculated from the measurement of initial isothermal magnetization versus magnetic field at various temperatures. The maximum entropy change S max M reaches the highest values of 3.31, 3.12, and 2.57 J/kg K in magnetic field. However, the relative cooling power decreases with Fe content from x = 227.44 to 188.68 J/kg for x = 0.00 to x = 0.15 compositions, respectively.

Influence of Fe3+ ion substitution on Structural, Magnetic Properties and Magnetoresistance Effect of Pr0.75Na0.05K0.20MnO3 System

“…The findings are consistent with a prior study that reported a similar suggestion [27,29,30]. 5 dominant effect of the super-exchange (SE) mechanism, which involves Fe 3+ -Fe 3+, Mn 3+ -Mn 3+ and Mn 4+ -Mn 4+ [24]. Furthermore, other research stated a similar suggestion as Fe 3+ doped in Pr0.67Sr0.16Ca0.17Mn0.75Fe0.25O3 manganite and reported that Fe 3+ ion does not participate in the double exchange (DE) mechanism [3].…”

“…The significant decrease in T C could be attributed to a weakening of ferromagnetic (FM) interaction caused by an enhancement of antiferromagnetic (AFM) ordering with Fe substitution [3]. A few reports similar finding regarding Fe substitution at Mn-site, suggesting that the weakening of FM interaction could also be due to the reduction of the Mn 3+ /Mn 4+ ratio [23,24].…”

“…In contrast, substitution of Fe in Pr 0.75 Na 0.05 K 0.20 Mn 0.95 Fe 0.05 O 3 sample exhibits insulating behavior over the whole temperature range from 30 K to 300 K for 0 T field. The observed behaviour may be explained by the dominant effect of the super-exchange (SE) mechanism, which involves Fe 3+ -Fe 3+ , Mn 3+ -Mn 3+ and Mn 4+ -Mn 4+ [24]. Furthermore, other research stated a similar suggestion such as Fe 3+ doped in Pr 0.67 Sr 0.16 Ca 0.17 Mn 0.75 Fe 0.25 O 3 manganite and reported that Fe 3+ ion does not participate in the double exchange (DE) mechanism [3].…”

“…This phenomenon can be attributed to the delocalization of charge carriers inside the sample as a result of the increased energy levels caused by the temperature increase [3]. 4 interaction could also be due to the reduction of the Mn 3+ /Mn 4+ ratio [23,24].…”