Properties of barium magnesium tantalate thin films produced by pulsed laser deposition

Barium magnesium tantalate (BMT), a complex perovskite oxide, has garnered interest because of promising dielectric properties, making it a candidate for advanced electronic applications. In this study, BMT thin films were deposited on various substrates by pulsed laser deposition (PLD) using solid-state Nd: YAG laser (266 nm) on substrates of Si, Pt/Si and Al2O3 under various substrate temperatures and oxygen partial pressures to assess the impact of these conditions on film properties. The techniques employed for the analysis of the thin films are: Spectroscopic ellipsometry (SE), Scanning electron microscopy (SEM), Energy Dispersive X-Ray (EDX). The optical constants determined using SE exhibited dependence on deposition parameters higher temperatures of substrate during the deposition yielded thin films with higher refractive indices. Moreover, substrate type played a critical role in film-substrate interface quality, influencing film texture and optical response and bandgap. The BMT thin films deposited on Pt/Si have better uniformity and structure, making them more suitable than Si or Al2O3 for BMT growth, and have refractive indices (n) of 1.82–2.29 at a wavelength of 589 nm, direct transition bandgaps of 3.77–4.15 eV and relative permittivity between 25.6 up to 62.5. The findings highlight the tunability of BMT thin film optical properties through careful control of PLD parameters showcasing correlations between growth conditions and functional properties.