Elastic constants of erbia single crystals

The elastic properties of single-crystalline erbia (Er2O3) at room temperat ure have been investigated using resonant ultrasound spectroscopy. The thre e independent stiffness constants of anisotropic Er2O3 cubic type-C crystal s have been measured. The values of the stiffness constants were c(11) 256. 4 GPa, c(12) = 1 16.8 Cpa, and c(44) = 75.2 GPa, From the stiffness constan ts, the estimated values for dense polycrystalline erbia for Young's modulu s, the shear modulus, the hulk modulus, and Poisson's ratio at room tempera ture were 179 GPa, 67 GPa, 183.3 Cpa, and 0337, respectively. The value of Young's modulus is a minimum along [001] and a maximum along [111], The val ue of the shear modulus is independent of the direction in the (001) and (1 11) planes, whereas it decreases in (1(1) over bar 0) from 75 GPa along [00 1] to 55 GPa along [110].