Comments on the paper “Insight on the growth and property studies of inorganic hydrated borate (Na6[B4O5(OH)4]3·8H2O) single crystal ̶ An effective third order nonlinear optical (NLO) material for optical limiting application”

Abstract

The authors of the title paper (Mater. Chem. Phy. 205 (2018) 138–146) claimed to have grown for the first time a new alkali metal borate with formula Na6[B4O5(OH)4]3·8H2O (I) by slow evaporation of an aqueous solution containing NaOH, H3BO3 and C3H4O4 in 3:1:1 mol ratio. In this letter to the Editor, many points of criticism concerning the crystal growth, structure characterization and interpretation of the spectral and thermal data of I are described to prove that it is improperly characterized.