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Density of valence states of the superionic conductor AgI
Author(s) -
Ostrow M.,
Goldmann A.
Publication year - 1979
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220950222
Subject(s) - valence (chemistry) , photoexcitation , wurtzite crystal structure , ion , density of states , tetrahedral symmetry , spectral line , chemistry , atomic physics , materials science , condensed matter physics , crystallography , physics , excited state , rotational symmetry , organic chemistry , hexagonal crystal system , mechanics , astronomy
Temperature dependent photoelectron spectra of AgI are measured between room temperature and 251°C for photon energies h ω = 21.2 and 40.8 eV. The spectra are decomposed into approximate partial p and d densities of valence states by using atomic cross sections for the corresponding partial photoexcitation probabilities. Significant abrupt reversible changes are observed in the partial p density of states at T c = 147°C, where the crystal structure changes from the wurtzite (β) phase to the superionic “disordered” α‐phase. In contrast, the partial d density of states, except for a slow continuous broadening with temperature, shows no sudden change at T c . The results strongly support the model, that in the α‐phase the Ag + ions occupy lattice sites with tetrahedral symmetry for a large fraction of the time.