Elastic and thermoelastic properties of l-glutamic acid hydrochloride

Abstract

Abstract The elastic constants, their temperature derivatives, and the thermal expansion of l-glutamic acid hydrochloride were measured. The crystals possess a remarkably high elastic and thermal anisotropy, which can be attributed to the preferential orientation of zigzag chains of hydrogen bonded molecules running parallel to the a3 axis. A similar behaviour was observed earlier in other hydrogen-bonded crystals like oxalic acid and acid salts of oxalic acid. Measurements of the piezoelectrical, electrooptical and nonlinear optical properties revealed only unexpected small effects, not high enough for a useful technical application.