Electronic Phase Separation in Multiferroic ${\rm Ba}_{3}{\rm NbFe}_{3}{\rm Si}_{2}{\rm O}_{14}$

The temperature dependence of magnetization and dielectric constant of polycrystalline Ba₃NbFe₃Si₂O₁₄ clearly indicates the presence of magnetically driven ferroelectric transition at 26 K, the Néel temperature T_N, depicting its multiferroic behavior. The isothermal magnetization variation with the field both below and above T_N however exhibits a hysteresis behavior with coercivity varying from 1600 Oe to 2500 Oe. These results combined with structural studies indicate the presence of multiple phases which are electronically and not structurally phase separated, similar to the phenomenon observed in magentoresistive perovskite compounds.