Raman and Fourier transform infrared spectroscopic investigation of the effects of Er3+ doping in barium titanate ceramics

In this work, we study the barium titanate doped different content Er3+ perovskite ceramics prepared by conventional solidstate sintering procedure. The as-made powder samples were pressed into a pellet shape and subsequently sintered at 1350 degrees C for 4 h in air. The structural, morphological, and optical properties of the synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microcopy (AFM), Raman and Fourier transform infrared spectroscopy (FTIR) spectroscopy, respectively. The XRD study revealed the formations of single phase tetragonal structure of barium titanate (BaTiO3). The SEM analysis shows that all of measured samples are characterized by polygonal grains. The uniform and homogeneous microstructure with grain sizes from 20 to 45 mu m is the main characteristic of the low doped samples (0.01 and 0.1 wt.% Er3+). For the samples doped with the higher dopant concentration (0.5 and 1.0 wt.%) the average grains sizes have been ranged from 2 to 15 mu m. Substitution of Er dopant into Ba-site reduced the grain sizes and roughness parameter of the BaTiO3 which was attributed to the smaller ionic radius of Er. The Raman and the FIR reflective spectra measured in this work were fitted. The intensity of the Raman and IR bands of Er3+ doped barium titanate is higher than that of undoped BT that could suggest a structure change from tetragonal to pseudo-cubic. FTIR shifts confirmed the incorporation of Er3+ in BaTiO3 at 1350 degrees C.