Magnetic and Raman spectroscopic studies of yttrium substituted BiFeO$_{3}$

As a room temperature multiferroic BiFeO$_{3 }$is attractive for a number of applications. However the relatively weak magnetism limits its suitability for applications. Bi$_{1-x}$Y$_{x}$FeO$_{3}$ (x=0, 0.05, 0.10, 0.15 and 0.20) ceramic samples have been prepared by sol-gel technique and thin films by metalorganic decomposition. X-ray diffraction, X-ray photoelectron and Raman spectroscopy measurements confirm that these ceramic and thin film samples are of single phase. More remarkably these Y modified BiFeO$_{3}$ samples exhibit enhanced room temperature magnetic and magnetodielectric properties, with the saturation magnetization approaching 25 emu cm$^{-3}$ for x=0.20. We discuss the correlation between the enhanced room temperature magnetization and two-phonon Raman modes in the context of investigating the origin of the magnetic properties in Bi$_{1-x}$Y$_{x}$FeO$_{3}$.