Structural Properties of Superconducting CaLi$_{2}$ At High Pressures

The hexagonal Laves phase of CaLi$_{2}$, a superconductor at high pressures, has been studied in the diamond anvil cell at varying pressures and temperatures. CaLi$_{2}$ is known to have a maximum superconducting transition temperature of 13 K at 40 GPa. X-ray diffraction measurements were done up to 40 GPa, from room temperature down to 10 K, and phase stability in relation to pressure and temperature has been examined. We present our study to provide more insight into phonon-mediated superconductors and simple-metal systems such as Li.\\[4pt] This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344 and under Contract DE-FG01-06NA26204. HPCAT use is supported by DOE-BES, DOE-NNSA, NSF, and the W.M. Keck Foundation. APS is supported by DOE-BES, under Contract No. DE-AC02-06CH11357.