Fe(iii) induced structural, optical, and dielectric behavior of cetyltrimethyl ammonium bromide stabilized strontium stannate nanoparticles synthesized by a facile wet chemistry route

Abstract

In this paper, we report the synthesis of Fe containing strontium stannate (SrSnO₃) nanoparticles by a facile cost-effective wet chemistry route using cetyltrimethyl ammonium bromide (CTAB) as a surfactant. Thermogravimetric analysis together with differential scanning calorimetric data revealed the formation of SrSn(OH)₆ as the initial compound, which led to the formation of SrSnO₃ via three main endothermic dehydration cycles. The X-ray diffraction patterns of the final compound revealed the formation of the orthorhombic phase of SrSnO₃ with Pbnm symmetry, and exhibited the contraction of cell volume with increase in Fe content. Raman spectra showed peaks at 220, 256, 306, 404, 452 and 561 cm⁻¹, which corresponds to Sn–O and O–Sn–O band stretching. The band gap values were found to be 4.17, 3.81 and 3.52 eV for the samples with 0, 2 and 4 at% Fe content, respectively. The photoluminescence spectra also confirmed the red shift of band emission peak observed around 370 nm. The relative permittivity was observed to be low and showed steady variation with temperature and Fe content. The dielectric relaxation time was found to decrease with temperature and increase with Fe content. The ac conductivity values were 3.23 × 10⁻⁸, 3.98 × 10⁻⁸ and 4.47 × 10⁻⁸ Ω⁻¹ cm⁻¹, and activation energy was found to be 0.22, 0.34 and 0.44 eV for pristine and Fe (2 and 4 at%). Conductivity analysis suggested the hopping of charge carriers in the crystal, as the possible mechanism for electric conduction.