Comments on "Investigation on synthesis, laser damage threshold, and NLO properties of L-asparagine thioacetamide single crystal for photonic device applications" [J Mater Sci: Mater Electron. 31, 13310-13320 (2020)]

Abstract

The authors of the title paper [J. Mater. Sci. Mater. Electron. 31, 13310-13320 (2020)] report to have grown a so-called L-asparagine thioacetamide (LATA) single crystal by slow evaporation of an aqueous solution containing L-asparagine monohydrate and thioacetamide in 1:1 ratio. The same research group has claimed in another paper [J. Mater. Sci. Mater. Electron. 31, 791-798 (2020)] to have grown a so-called NLO-active potassium hydrogen phthalate fumaric acid crystal (KHPF). In this comment we prove that LATA and KHPF are improperly characterized crystals and both papers are erroneous.