Synthesis of Sm3+ and Gd3+ Ions Embedded in Nano-Structure Barium Titanate Prepared by Sol-Gel Technique: Terahertz, Dielectric and Up-Conversion Study

Abstract

Nano-structure Barium Titanate (BaTiO3) doped with 1 mole% Sm3+ and Gd3+ ions have been synthesized by modified sol-gel process. The tetragonal perovskite structure has been demonstrated by means of X-ray diffraction and selected area electron diffraction obtained by high resolution transmission microscopy. The XRD and HRTEM have been used for estimation the grain size, which found to be around 38.36 and 33.26 nm. The scanning electron microscope micrographs asserted the formation of agglomerated particles, which is characteristic of many nano-systems. The green emission has been observed at 528, 567 and 597 nm, whereas red group emission at 604, 611, 632, 643, 660, 672, 688, 716 and 732. The thermal stability and the purity of the synthesized material were confirmed by the results of Thermogravimetric Analysis (TGA) and differential scanning calorimetry (DSC). Two relaxation processes were observed in the dielectric loss εʹ as well as in the modulus spectra of both samples. The dielectric behavior was further discussed in the range of terahertz by using the time domain terahertz spectrophotometer. the refractive index in terahertz were found to be dwindle, whereas the absorption coefficient improved upon increasing THz frequencies.