Synthesis and characterization of gallium doped and chitosan assisted multiferroic bismuth ferrite by hydrothermal method / Muhammad Safwan Sazali

The rapid development and research study towards multiferroic materials which is BiFeO3 was due to the characteristics possess by the material where it can exists at room temperature which rarely happen for other multiferroic materials. In the present study, the main focus has been dedicated to synthesis pure BiFO3 and modified BiFeO3 via hydrothermal method. Structural, optical and magnetic properties of all samples have been investigated. X-rays diffraction (XRD) study was carried out to determine the phase presence in the materials and the obtained results shows the presence of BiFeO3 peaks for all samples, pure BiFeO3 (Ga3+; x = 0%), 0.24 g Chitosan assisted BiFeO3, Bi1-xGaxFeO3 (x = 1%, 3% and 5%). For Bi1-xGaxFeO3 (x = 5%), a secondary phase which may associated with Bismuth Oxide, Bi2O3 was detected from Rietveld refinement analysis via GSAS software. Scanning electron microscope (SEM) analysis was carried out to observe the morphology of all samples pure BiFeO3 and modified BiFeO3 where the results show changes in particles size and also all the sample possess agglomeration. The agglomeration was much more controlled and consistent for 0.24 g Chitosan assisted BiFeO3. For optical study, the value of band gap obtained for Ga3+ doped samples are 1.70 eV (x = 0%), 1.70 eV (x = 1%), 1.82 eV (x = 3%) and 1.78 eV (x = 5%) while for 0.24 g Chitosan assisted BiFeO3 is 1.16 eV. The analysis of magnetic properties was carried out to determine the effect towards BiFeO3 before and after modification. The hysteresis loops of anti-ferromagnetic possess by BiFeO3 shows an improvement when doped with Ga3+ and with the assist of 0.24 g Chitosan on BiFeO3. The shape of the graph changes gradually from linear to ‘S’ shapes with the increasing of Ga3+ weight percentage. In addition, the coercivity field also decrease from 323.07 G (x = 0%), 33.27 G (x = 1 %), 229.73 G (x = 3%), 28.983 G (x =5 %) suggested that the samples have lower losses and can be easily magnetized and demagnetized. Chitosan assisted BiFeO3 sample show a small value of coercivity which is 20.877 G compared to pure BiFeO3 which is 323.07 G.