Comments on the paper "Customizing optical and dielectric traits of ammonium dihydrogen phosphate (ADP) crystal exploiting Zn sup(2+) ion for photonic device applications"

Abstract

The authors of the title paper (Chin J Phys 63 (2020) 70-77) claim to have grown a Zn sup(2+) ion influenced ammonium dihydrogen phosphate (Zn-ADP) crystal by the slow solvent evaporation technique. In this comment, many points of criticism, concerning the crystal growth and characterization of the so-called Zn-ADP crystal are discussed to prove that it is a dubious material and the title paper is erroneous.