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Localized 4f States and Dynamic Jahn-Teller Effect in PrO2

A. T. Boothroyd·C. H. Gardiner·S. J. S. Lister·P. Santini·B. D. Rainford·L. D. Noialles·D. B. Currie·R. S. Eccleston·R. I. Bewley
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Abstract

Neutron spectroscopic measurements of the magnetic excitations in PrO$_2$ reveal (1) sharp peaks characteristic of transitions between levels of the $4f^1$ configuration of Pr$^{4+}$ split by the cubic crystal field, and (2) broad bands of scattering centred near 30 meV and 160 meV. We present a simple model based on a vibronic Hamiltonian that accounts for the main features of the data. The analysis shows that $90\pm10$% of the Pr ions have a localized $4f^1$ configuration and provides strong evidence for a dynamic Jahn-Teller effect in the $Γ_8$ electronic ground state.

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A. T. Boothroyd, C. H. Gardiner, S. J. S. Lister, P. Santini, B. D. Rainford, L. D. Noialles, D. B. Currie, R. S. Eccleston, R. I. Bewley. 2001-01-08. Localized 4f States and Dynamic Jahn-Teller Effect in PrO2. https://doi.org/10.1103/physrevlett.86.2082

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