Improved ferroelectric, magnetic and photovoltaic properties of Pr doped multiferroic bismuth ferrites for photovoltaic application

Multiferroic Bi1-xPrxFeO3 ( x=0.0, 0.05, 0.10, 0.15, 0.20) ceramic samples have been synthesized by sol-gel method. A detailed investigation has been made on structural, magnetic, electrical, optical and photovoltaic properties of Pr doped bismuth ferrites. A structural phase transition has been observed from ( R3c) rhombohedral for pristine sample BiFeO3 to ( Pnma phase) orthorhombic structure for Bi0.85Pr0.15FeO3 sample. A coexistence of ( R3c) rhombohedral and ( Pnma) orthorhombic phases were observed for 0.05 < x <= 0.15 samples. It is observed that the dielectric properties depend on Pr percentage in BFO. The values of dielectric constants for BFO, epsilon'=64.21 and epsilon ''=9.09 have been increased with Pr doping and maximum for Pr=0.20 sample with values, e'=111.79 and e ''=55.79 at 100 Hz. The magnetization value 0.24 emu/g for BFO increases with Pr doping to maximum value 0.50 emu/g for Bi0.8Pr0.2FeO3 sample. The P-E loop study of the samples shows the modified ferroelectric behavior with Pr doping. The enhanced ferroelectric properties show increase in photocurrent upon illumination of light. Energy band gap value Eg=2.44 eV for BFO, decreases with Pr doping and minimum value, Eg=2.27 eV for Pr=0.15 sample. The improved ferroelectric, magnetic and photovoltaic properties of Pr doped bismuth ferrites offer a new application in ferroelectric/multiferroic based photovoltaic devices.