Growth mechanism, dislocation etching and mechanical properties of L-arginine phosphate and deuterated L-arginine phosphate

Single crystals of L-arginine phosphate monohydrate (LAP) and its deuterated analog (dLAP) were grown from aqueous solutions. Effect of pH variation on growth of microbes in these solutions was studied. Efforts were undertaken to minimize microbial incorporation into these crystals. The grown crystals were characterized by recording the powder diffraction and identifying the diffracting planes. Dislocation contents of these crystals were estimated by etching the cleavage planes using a mixture of glacial acetic and ethanol. Growth features on habit faces of LAP and dLAP were studied. Growth takes place on the (100) plane predominantly by spreading of layers which manifests as a step pattern. Hillocks were observed on $(0\={1}0), (1\={1}0)$ and $(\={1}10)$ habits faces. Load dependence of microhardness was evaluated for LAP and dLAP.