Investigate the AC conductivity, ferroelectric studies, and mössbauer spectroscopy studies of La2SrFe2TiO9 triple perovskite for various applications

Abstract

La₂SrFe₂TiO₉ Triple perovskite, prepared via the solid-state reaction method, exhibits an orthorhombic structure with space group Pnma as confirmed by X-ray diffraction studies. The dielectric properties of the material were investigated in the temperature range of 100–400 K within the frequency range of 20 Hz–2 MHz. We have seen that the material’s dielectric constant decreases with the increase in the frequency due to the space polarisation mechanism and its increase with temperature due to the thermal activation of the charge carriers. Jonscher’s Power law explains the AC conductivity mechanism of the sample, and we have seen that the material shows two types of conduction mechanisms: the Carrier Barrier Hopping Mechanism (CBH) and the Non-overlapping Small polar tunneling (NSPT) model. The shifting of the relaxation peak towards a higher frequency with an increase in temperature ensures its thermally activated nature. From the ferroelectric studies, we have seen that the material possesses ferroelectric behavior. The valence state of the Fe atom, as determined from measurements of the Mossbauer effect of ⁵⁷Fe at room temperature, indicated that the iron ion exists in the Fe³⁺ high spin state based on the values obtained for the isomer shift. Additionally, the material's ability to exhibit high conductivity coupled with low tangent loss, attributed to oxygen vacancies, establishes La₂SrFe₂TiO₉ as a highly promising option for use in electronics, magnetoelectric, spintronics, and photocatalysis.