The High-Pressure Melt Curve and Phase Diagram of Lithium

Journal Article · 05 August 2019 · Physical Review Letters

DOI: https://doi.org/10.1103/PhysRevLett.123.065701 · OSTI ID:1542457

Frost, Mungo ^[1]; Kim, Jongjin B. ^[2]; McBride, Emma E. ^[2]; Peterson, J. Ryan ^[3]; Smith, Jesse S. ^[4]; Sun, Peihao ^[3]; Glenzer, Siegfried ^[2]

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1. SLAC National Accelerator Lab., Menlo Park, CA (United States); SLAC National Accelerator Laboratory
2. SLAC National Accelerator Lab., Menlo Park, CA (United States)
3. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States). Physics Dept.
4. Argonne National Lab. (ANL), Argonne, IL (United States).X-ray Science Division

This study investigates the phase diagram of lithium at temperatures of 200K to 400 K, to pressures over 100GPa using X-ray diffraction in diamond anvil cells, covering the region in which the melting curve is disputed. To overcome degradation of the diamond anvils by dense lithium we utilize a rapid compression scheme taking advantage of the high flux available at modern synchrotrons. Our results show the hR1 and cI16 phases to be stable to higher temperature than previously reported. The melting minima of lithium is found to be close to room temperature between 40GPa and 60GPa, below which the solid is crystalline. Finally, analysis of the stability fields of the cI16 and oC88 phases suggest the existence of a triple point between these and an undetermined solid phase at 60GPa between 220K and 255 K.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
• Grant/Contract Number: AC02-06CH11357; AC02-76SF00515
• OSTI ID: 1542457
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 6 Vol. 123; ISSN 0031-9007
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English