| AVS 60th International Symposium and Exhibition | |
| Actinides and Rare Earths Focus Topic | Monday Sessions |
| Session AC+MI+SA+TF-MoM |
| Session: | Actinides and Rare Earths: Experiment and Electron Correlation |
| Presenter: | M.J. Lipp, Lawrence Livermore National Laboratory |
| Correspondent: | Click to Email |
High-pressure x-ray emission measurements of the Lγ1 (L2N4) emission line were used to decide the longstanding debate over the nature of the famous iso-structural (γ-α) volume collapse at 0.75 GPa in elemental cerium that ends in a critical point at 1.5 GPa and 480 K. The satellite structure of this line offers direct access to the total angular momentum observable <J 2> as shown by extended local atomic model calculations and experiences a 30% step-like decrease across the volume collapse. This validates the Kondo model in conjunction with previous measurements of the equation of state at high temperature that were also well fit by the Kondo volume collapse model plus a quasiharmonic representation of the phonons - but could also be reproduced within the Hubbard-Mott framework. The remaining satellite in the α -phase after the volume collapse does not change significantly over the pressure range studied. Direct comparison is made with previous predictions by dynamical mean field theory.
This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52- 07NA27344 and funded by the Laboratory Directed Research and Development Program at LLNL under project tracking code 12-LW-014. Portions of this work were performed at HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory. HPCAT operations are supported by DOE-NNSA under Award No. DE-NA0001974 and DOE-BES under Award No. DE-FG02-99ER45775, with partial instrumentation funding by NSF. APS is supported by DOE-BES, under Contract No. DE-AC02-06CH11357.