Premium
Pressure‐Induced Valence Transitions in Rare Earth Chalcogenides and Pnictides
Author(s) -
Svane A.,
Strange P.,
Temmerman W.M.,
Szotek Z.,
Winter H.,
Petit L.
Publication year - 2001
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 - 10.1002/1521-3951(200101)223:1<105::aid-pssb105>3.0.co;2-i
Subject(s) - isostructural , delocalized electron , cerium , valence (chemistry) , valence electron , atom (system on chip) , electronic structure , electron , electron configuration , condensed matter physics , chemistry , bulk modulus , density functional theory , lattice constant , ion , atomic physics , crystallography , crystal structure , physics , computational chemistry , inorganic chemistry , organic chemistry , quantum mechanics , computer science , diffraction , embedded system , optics
The electronic structure of rare earth chalcogenides and pnictides is calculated with the ab‐initio self‐interaction corrected local‐spin‐density approximation (SIC‐LSD). This approach allows both an atomic‐like description of the rare earth f‐electrons and an itinerant description of other electronic degrees of freedom. Specifically, different formal valencies of the rare earth atom, corresponding to different f‐shell occupancies, can be studied and their energies compared, leading to a first‐principles theory for pressure‐induced valence transitions. SIC‐LSD calculations for cerium monopnictides and monochalcogenides, Yb monochalcogenides, and EuS are presented. The observed equilibrium lattice constants are well reproduced assuming a trivalent Ce configuration and divalent Eu and Yb configurations. The trends in the high pressure behavior of these systems are discussed. With applied pressure, isostructural phase transitions are found to occur in CeP and CeS, caused by the delocalization of the Ce f‐electron, while in the heavier Ce compounds, the structural B1 → B2 transition happens before f‐electron delocalization occurs. Similarly, both Eu and Yb chalcogenides transfer to trivalent configurations with pressure, in accordance with observation.