ic7b01405_si_001.pdf (103.38 kB)
Download fileCovalency Competition in the Quadruple Perovskite CdCu3Fe4O12
journal contribution
posted on 2017-07-19, 19:14 authored by Ikuya Yamada, Akihiko Takamatsu, Naoaki Hayashi, Hidekazu IkenoCadmium
ions (Cd2+) are similar to calcium ions (Ca2+) in size, whereas the Cd2+ ions tend to form covalent
bonds with the neighboring anions because of the high electronegativity.
The covalent Cd–O bonds affect other metal–oxygen bonds,
inducing drastic changes in crystal structures and electronic states.
Herein, we demonstrate high-pressure synthesis, crystal structure,
and properties of a new quadruple perovskite CdCu3Fe4O12. This compound exhibits an electronic phase
transition accompanying a charge disproportionation of Fe ions without
charge ordering below ∼200 K, unlike charge-disproportionation
transition with rock-salt-type charge ordering for CaCu3Fe4O12. First-principle calculations and Mössbauer
spectroscopy display that covalent Cd–O bonds effectively suppress
the Fe–O bond covalency, resulting in an electronic state different
from that of CaCu3Fe4O12. This finding
proposes covalency competition among constituent metal ions dominating
electronic states of complex metal oxides.
History
Usage metrics
Read the peer-reviewed publication
Categories
Keywords
charge-disproportionation transitioncrystal structureFirst-principle calculationsFe ionsform covalent bondscharge disproportionationrock-salt-type chargecrystal structuresQuadruple Perovskite CdCu 3 Fe 4 O 12 Cadmium ionsphase transitioncompound exhibitsCaCu 3 Fe 4 O 12Covalency Competitionperovskite CdCu 3 Fe 4 O 12metal oxidescalcium ionsconstituent metal ionscovalency competition