Damping of antiferromagnetic spin waves by valence fluctuations in the double layer perovskite YBaFe2O5

TitleDamping of antiferromagnetic spin waves by valence fluctuations in the double layer perovskite YBaFe2O5
Publication TypeJournal Article
Year of Publication2007
AuthorsChang S, Karen P, Hehlen MP, Trouw FR, McQueeney RJ
Journal TitlePhysical Review Letters
Volume99
Pages037202
Date PublishedJul
Type of ArticleArticle
ISBN Number0031-9007
Accession NumberISI:000248194700051
KeywordsCHARGE, electronic-structure, EXCHANGE, oxides, series
Abstract

Inelastic neutron scattering experiments show that spin dynamics in the charge-ordered insulating ground state of the double layer perovskite YBaFe2O5 is well described in terms of e(g) superexchange interactions. Above the Verwey transition at T-V=308 K, t(2g) double exchange-type conduction proceeds within antiferromagnetic FeO2-BaO-FeO2 double layers by an electron hopping process that requires a spin flip of the five-coordinated Fe ions, costing an energy of 5 < J > S-2 approximate to 0.1 eV. The hopping process disrupts near-neighbor spin correlations, leading to massive damping of zone-boundary spin waves.

DOI10.1103/PhysRevLett.99.037202
Alternate JournalPhys. Rev. Lett.