Formation of magnetite in bismuth ferrrite under voltage stressing

摘要

Micro-Raman studies show that under ～700 kV/cm of dc voltage stressing for a few seconds, magnetite Fe_3O_4 forms in thin-film bismuth ferrite BiFeO_3, probably due to phase separation. No evidence is found spectroscopically of hemite α-Fe_2O_3, maghemite γ-Fe_2O_3, or Bi_2O_3. This may relate to the controversy regarding the magnitude of magnetization in BiFeO_3.