Fig. 5
From: Characteristic fast H− ion conduction in oxygen-substituted lanthanum hydride
Anharmonicity of H− vibration in LaH3−2xOx. a Schematic illustration of energy landscape of H− along the migration path for LaH3-2xOx at x = 0.25. The disordering of H− at the Oc site is also shown schematically. b Anharmonic oscillation of H− in LaH3. Left figure represents the anharmonic oscillator potential of light and highly polarizable H−, and right shows the crystal structure of LaH3 where the rhombic dodecahedrons of LaH14 are emphasized. The light mass and high polarizability of H−, and the framework structure composed of densely packed H− in LaH3−2xOx, are crucial factors that impose anharmonicity
