Localized 4f states and dynamic Jahn-Teller effect in PrO2

• Published in: Physical review letters Vol. 86; no. 10; pp. 2082 - 2085
• Main Authors: Boothroyd, A T, Gardiner, C H, Lister, S J, Santini, P, Rainford, B D, Noailles, L D, Currie, D B, Eccleston, R S, Bewley, R I
• Format: Journal Article
• Language: English
• Published: United States 05-03-2001
• ISSN: 0031-9007
• DOI: 10.1103/PhysRevLett.86.2082

Neutron spectroscopic measurements of the magnetic excitations in PrO2 reveal (1) sharp peaks characteristic of transitions between levels of the 4f(1) configuration of Pr4+ split by the cubic crystal field, and (2) broad bands of scattering centered near 30 and 160 meV. We present a simple model based on a vibronic Hamiltonian that accounts for these contrasting features of the data. The analysis shows that 90%+/-10% of the Pr ions have a localized 4f(1) configuration and provides strong evidence for a dynamic Jahn-Teller effect in the gamma(8) electronic ground state.