Electronic, Structural, Optical and Mechanical Properties of Cubic Structured Ln2X3 (Ln = La→Lu & X=O,S): An Empirical Investigation

Abstract

In this publication, we have examined the structural, optical, and mechanical features of cubic structured lanthanide Ln2X3 (Ln = La→ Lu and X = O, S) series using the valence electron plasma oscillation theory of solids. Using the Chemical bond theory of solids, which was created by Phillips and Van-Vechten, we have further confirmed our findings. Unfortunately, it has been discovered that the Phillips and Van-Vechten (PVV) dielectric description is applicable exclusively to semiconductors and insulators. It is shown that an empirical relationship previously presented by Yadav and Bhati [D.S. Yadav, J. Alloys and Comp. 537, 250 (2012); D.S. Yadav, and D.V. Singh, Phys. Scr. 85, 015701 (2012); D.S. Yadav, J. Mater. Phys. Chem. 3(1), 6-10 (2015); R. Bhati, et al., Mater. Phys. Mech. 51, 90 (2023); R. Bhati, et al., East Eur. J. Phys. (1), 222 (2023).] relating the plasmon energy of complex structured solids, rock salt, and zinc-blende to their electronic, mechanical, static, and dynamical properties which can be applied to the cubic structured lanthanide (Ln2S3 & Ln2O3) series with only minor modifications. Considering the well-known theory of dielectric for solids, an alternative technique has been devised to evaluate the electronic, structural, mechanical, and optical properties of these materials, including their band gap (∆Eg in eV), optical dielectric constant, homopolar and heteropolar gaps, average energy gaps, chemical bond ionicity, and bulk muduli. An estimate was computed based on the almost inverse relationship between the plasmon energy of these compounds and their optical, mechanical, structural, and electrical characteristics. For these substances, the expected values of the aforementioned parameters form a straight line when plotted on a log-log scale against the plasmon energy (ħωp). We examined the C‑type Ln2X3 compounds using the recommended methods, and the values we estimated are in good agreement with the values obtained from modified PVV theory and other comparable experimental and theoretical data that is currently available.

Keywords

• electronic properties
• optical properties
• structural properties
• mechanical properties
• ln2o3
• ln2s3
• plasma energy