Figure 9
From: Atomic scale insights on the growth of BiFeO3 nanoparticles
Pictorial summary of the results of this work showing the effect of calcination of the precursor gel obtained using sol–gel method of preparation of BiFeO3 with tartaric acid as the fuel based on Mӧssbauer studies. Mӧssbauer results in the dried precursor gel reveal the presence of SPM particles of BiFeO3 along with the very fine paramagnetic nanoparticles of Bi25FeO40. Mӧssbauer results imply the coalescence of nanoparticles of BiFeO3 marked as stage-I, followed by significant growth of nanocrystallites of BiFeO3 in stage-II over a narrow temperature interval of 700–723 K, with stage-III is understood to be due to coarsening of nanocrystallites in to polycrystallites of BiFeO3. Significant magneto electric coupling effect is elucidated in the precursor gel calcined at 723 K. Increase in the value of the mean hyperfine field at Fe sites in BiFeO3 due to increase in the size of nanocrystallites of BiFeO3 as caused by calcination is also shown.
