Comments on the paper “Synthesis and characterization of inorganic nonlinear optical material: Potassium sodium hydroxide borate hydrate (KSB) single crystal”

Abstract

The authors of the title paper (Mater. Lett. 188 (2017) 156–158) claimed to have grown potassium sodium hydroxide borate hydrate (KSB) single crystal and reported its mechanical properties in a subsequent paper (Mater. Lett. 215 (2018) 165–168). In this letter, many points of criticism concerning the crystal growth, structure characterization and interpretation of the spectral and thermal data of the so-called KSB crystal are described to prove that it is a dubious material.