Single-crystal elastic and thermodynamic properties of γ-LiAlO2

Abstract

The elastic properties of γ-LiAlO2 were reinvestigated with the aid of resonant ultrasound spectroscopy (RUS) at ambient conditions. A strong discrepancy of the elastic coefficients derived by RUS can be found from the experimental results from literature, where c12 and c13 deviate from our results by about 15 % (24 GPa) and 60 % (42 GPa), respectively. In contrast to the experimental cij from literature we can recognize a good agreement between the elastic coefficients derived from RUS and the values using density functional theory (DFT). The dielectric permittivity was measured on large plane-parellel plates and the piezoelectric stress coefficient e123 = 0.14 C m −2 was derived from RUS measurements at ambient conditions. The heat capacity between 4 K -398 K has been obtained by microcalorimetry using a relaxation calorimeter. The Debye temperature was derived from heat capacity measurements (ΘCp = 676 K) and from RUS measurements (Θ elastic = 688 K).

Elasticity of Dense Metal–Organic Framework Compounds

“…RUS spectra are typically obtained in the region between 50 and 2000 kHz. The elastic properties of ZnGF and CuGF were studied by RUS using an ambient temperature RUS device. − The samples’ sizes were of 5.351(2) × 5.091(2) × 4.252(2) mm 3 and 5.961(2) × 3.578(2) × 4.376(2) mm 3 for ZnGF and CuGF , respectively. The samples were slightly clamped between an ultrasound generator and detector.…”