Comment on the paper titled “Study of mechanical, optoelectronic, and thermoelectric aspects of lithium-based double perovskites Li2AgSbX6 (X = Cl, Br, I) for energy harvesting applications” [Mater. Sci. Eng.: B, 309 (2024) 117651]

Abstract

In this comment, we have recalculated the Vickers hardness values of double perovskites Li₂AgSbX₆ (X = Cl, Br, I) compounds studied by Nazir et al. [1] using the bulk and shear moduli provided by the authors. The authors reported that these compounds are ultra-hard materials. However, a careful review of the paper revealed a significant numerical error in the hardness calculations, resulting in misleading interpretations. The correction of these values is important for the accurate interpretation of the mechanical properties of the compounds. The Vickers hardness values, which we have recalculated correctly, will enable a more accurate assessment of the mechanical properties of the compounds.