Unveiling the Structural and Optical Properties of Samarium Titanates Pyrochlore, Sm2Ti2O7

Abstract

A magnetic system whose geometry prevents all pairwise spin interactions from being fulfilled simultaneously to minimize the energy is said to be frustrated. These systems are prevalent throughout all disciplines of physical and chemical study. This article reports a detailed structural and optical analysis of such frustrated Sm2Ti2O7 (STO), a pyrochlore structure. The ordered pyrochlore, STO of cubic symmetry, space group Fd3¯m [no. 227], has been synthesized using the standard solid-state reaction method. The Tauc’s plot reveals a direct band gap value of 3.8 eV from ultraviolet-visible reflectance data. Photoluminescence studies for STO using 280 nm excitation wavelength show the most intense emission peak at 395 nm, 468 nm, and other weak emissions at 368 nm, 412 nm, 430 nm, 449 nm, and 514 nm corresponding to the respective electronic transitions, indicates that the materials show photoluminescence properties. However, the unique characteristics of Sm2Ti2O7, including its wide band gap, photoluminescence, and high refractive index, make it a promising candidate for various magneto-optical, solid oxide fuel cell device fabrication applications.