Quantification of charge carriers participating antiferromagnetic to weak ferromagnetic phase transition in Na doped LaFeO3 nano multiferroics
Multiferroic La1-xNaxFeO3 (x = 0.0, 0.05, 0.10, and 0.15) nanoparticles have been synthesized by the citrate sol-gel auto-combustion method. It is uniquely known for the homogeneous distribution of particle size due to the low temperature synthesis condition. The Rietveld refinement of the X-ray dif...
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Veröffentlicht in: | Journal of applied physics 2018-08, Vol.124 (8) |
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Sprache: | eng |
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Zusammenfassung: | Multiferroic La1-xNaxFeO3 (x = 0.0, 0.05, 0.10, and 0.15) nanoparticles have been synthesized by the citrate sol-gel auto-combustion method. It is uniquely known for the homogeneous distribution of particle size due to the low temperature synthesis condition. The Rietveld refinement of the X-ray diffraction pattern has exhibited the single phase orthorhombic perovskite structure. It is confirmed from micro-Raman analysis that hole doping (Na) produces a structural crossover from the Pnma to Pbnm space group. The red shift observed in UV-visible spectroscopy indicates the shrinkage of bandgap. Photoluminescence analysis supports independently the bandgap shrinkage by the existence of violet-blue emission due to charge disproportion by oxygen related defects. A changeover from semiconductor to metallic nature accompanied by the hopping of charge carriers from Fe3+ to Fe2+/Fe4+ exchange interaction has revealed a considerable increase in conductivity and dielectric constant. Finally, the doping helps to induce transition from an antiferromagnetic to a weak ferromagnetic state due to free carrier concentration. It is found that the hole driven Fe3+ to Fe2+/Fe4+ exchange interactions with change in the Bohr magneton values from 5.9 μB to 4.9/4 μB are responsible for variation in the magnetization values. |
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ISSN: | 0021-8979 1089-7550 |
DOI: | 10.1063/1.5034180 |