Shock synthesis of lanthanum-III-pernitride

Abstract

Lanthanum-III-pernitride is unique amongst pernitrides because of the seemingly misfit charge balance and stoichiometry. La⁺³N₂ has been predicted to be stabilized by resonance between two mesomeric states of bonding in the pernitride group, which include a remarkable N‒N single bond limiting state. However, successful synthesis of this compound remained extant. Here, we report synthesis of LaN₂ through shock-driven decomposition of lanthanum nitrate. The result is noteworthy as a first quantitative measure of the stability of N‒N single bonds in solids formed at GPa-level pressure and with respect to a possible cross-over of redox potentials in the nitrogen- and oxygen-systems at high pressure and temperature.

Keywords:

• crystallography
• Landau theory
• diffraction
• shock
• geophysics

Acknowledgements

This research was supported by NNSA Cooperative Agreement DE-FC88-01NV14049. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

Notes

^†This article was first presented at the joint IUCr Commission on High Pressure 2012 - Quantum Beam Science Directorate Meeting “Advances in Crystallography at High Pressures” International Symposium (IUCrHP2012/QuBS2012), September 23–27 2012, Mito, Japan.