abstract
Ba2Zn2Fe28O46 hexaferrite was prepared using green synthesis with different quantities of ginger root extract (obtained from 0.0, 17.5, 35, 52.5 and 70 g of ginger root) as a natural antioxidant reducing agent. The dried precipitates were preheated at 550 degrees C/4 h and finally heated at 1200 degrees C/5 h. The effect of ginger root extract on structural, phase purity, magnetic, Mossbauer and low frequency (10 Hz-2 MHz) dielectric properties were investigated. XRD analysis of samples prepared with extracts from 35, 52.5, and 70 g of ginger depicted pure X-phase, while the other samples (0.0, 17.5 g) showed the secondary phase of M-type (BaM, BaFe12O19) along with hematite (12% alpha-Fe2O3). Hence, samples with greater amounts of ginger extract formed single-phase X-type hexaferrite. Saturation magnetization (Ms) varied from 40.8 A m(2)/kg without ginger extract to 69.8 A m(2)/kg with extract from 52.5 g ginger, and was <65 A m(2)/kg for all samples made with the ginger extract. All synthesized samples were relatively soft ferrites, and coercivity increased with amount of ginger extract used. The Mossbauer spectra explored six sextets of five magnetic sub-lattices, and the presence of Fe3+ (99.4-97.3 %) and Fe2+ (0.6-2.7 %) ions, with more Fe2+ present in the extract-derived samples. The variations in M-S based on hysteresis loops were in agreement by MOssbauer spectroscopy. The use of the extract also significantly reduced the grain size, from 3.3 mu m without ginger extract to 0.7-1.7 mu m with the extract, with a corresponding increase in coercivity from 16 to 40-80 kA/m. The samples prepared with extracts from 35 g to 52.5 g ginger root possessed considerable real dielectric constant compared to the others, but the extract also increased conductivity in the high-frequency region. Complex impedance displayed low values in the high-frequency region, and Cole-Cole plots revealed that the main contribution to conductivity in extract-based samples was from the grains. The reducing action of the green extract not only produced single phase X ferrite, but it also reduced grain size to similar to 1-2 mu m and greatly increased M-S.
keywords
SOL-GEL; MAGNETIC-PROPERTIES; GLASS-CERAMICS; IRON-OXIDE; IMPEDANCE; BEHAVIOR; MG; NANOPARTICLES; MODULUS; CONDUCTIVITY
subject category
Materials Science
authors
Kagdi, AR; Pullar, RC; Meena, SS; Carvalho, FE; Sandhu, CS; Jotania, RB; Prajapat, CL; Basak, CB
our authors
acknowledgements
Amrin R. Kagdi would like to acknowledge the Ministry of Minority Affairs, Govt. of India for providing Maulana Azad National Fellowship (No. F1-17.1/2013-14/MANF-2013-14-MUS-GUJ-28541) .This work was partly supported by DRS-SAP grant (Phase-II, No. F-530/17/DRS-II/2018 (SAP-I) ) of University grant commission, New Delhi, India, and DST-FIST grant ( (level-I, No. SR/FST/PSI-198/2014) ) of Department of Science and Technology, India. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement, and R.C. Pullar thanks FCT (Fundacao para a Ciencia e a Tecnologia, Portugal) grant IF/00681/2015 for sup-porting this work.