AUTHOR=Singh Baltej , Gupta Mayanak K. , Mittal Ranjan , Zbiri Mohamed , Hodgson Sarah A. , Goodwin Andrew L. , Schober Helmut , Chaplot Samrath L. 

TITLE=Anomalous Lattice Dynamics in AgC4N3: Insights From Inelastic Neutron Scattering and Density Functional Calculations

JOURNAL=Frontiers in Chemistry

VOLUME=6

YEAR=2018

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2018.00544

DOI=10.3389/fchem.2018.00544

ISSN=2296-2646

ABSTRACT=<p>We have performed temperature dependent inelastic neutron scattering measurements to study the anharmonicity of phonon spectra of AgC<sub>4</sub>N<sub>3</sub>. The analysis and interpretation of the experimental spectra is done using <italic>ab-initio</italic> lattice dynamics calculations. The calculated phonon spectrum over the entire Brillouin zone is used to derive linear thermal expansion coefficients. The effect of van der Waals interaction on structure stability has been investigated using advanced density functional methods. The calculated isothermal equation of states implies a negative linear compressibility along the c-axis of the crystal, which also leads to a negative thermal expansion along this direction. The role of elastic properties inducing the observed anomalous lattice behavior is discussed.</p>