Electric, magnetic and optical limiting (short pulse and ultrafast) studies in phase pure (1 - x)BiFeO₃-xNaNbO₃ multiferroic nanocomposite synthesized by the pechini method

The perovskite (1 - x)BiFeO₃-xNaNbO₃ nanocomposite was successfully synthesized by Pechini method and crystallographic information was obtained from XRD and TEM analysis. Structural analysis using XRD and TEM shows that phase pure samples were obtained with reduced particle size. The observations reveal that particle size plays a crucial role in deciding the electric and magnetic properties. The multiferroic character of nanoparticles is confirmed through magneto electric (ME) coupling studies. The good coexistence of ferroelectric and ferromagnetic behaviors in the composite provides the possibility to achieve a measurable ME effect. The highest value of the magneto electric coefficient (α) is observed for x = 0.1 (α = 0.13 V cm^-1 Oe^-1) and it reduces for higher x values. Magnetization measurements for x = 0.1 show a small hysteresis at 6 K which also confirms the presence of the magnetic phase at low temperature while the usual antiferromagnetic behavior of BFO is found at 300 K. The reduced size and absence of impurity could be the reason for the enhancement in electrical properties. Low loss tangent values observed in the samples display a remarkable improvement. Open aperture Z-scan measurements reveal a nonlinear absorption behavior, which results in good optical limiting when excited with short pulse (nanosecond) as well as ultrafast (femtosecond) laser pulses.