Work

Disorder-induced damping of spin excitations in Cr-doped BaFe 2 As 2

Year: 2026

Type: article

Abstract: In doped Hund's metals, such as the iron-based superconductors, effects like charge doping and chemical pressure are often considered the dominant factors. Partial chemical substitution, however, inevitably introduces disorder. Here, we investigate spin excitations in Ba( Fe 1 − x Cr x ) 2 As 2 (CrBFA) by high-resolution resonant inelastic x-ray scattering for samples with x = 0 , 0.035 , and 0.085 . In CrBFA, Cr acts as a hole dopant, but also introduces localized spins that compete with Fe-derived magnetic excitations. We found that the Fe-derived magnetic excitations are softened and damped, becoming overdamped for x = 0.085 . At this doping level, complementary angle-resolved photoemission spectroscopy measurements show increased electronic localization and a suppression of the nematic d x z / d y z band splitting present in the parent compound. We thus propose a localized spin model that explicitly incorporates substitutional disorder and Cr local moments, successfully reproducing our key observations. Our findings reveal a case where disorder dominates over charge doping in the case of a Hund's metal.

Source: Physical Review Research

DOI: 10.1103/rkjn-hf7z

Authors: Marli R. Cantarino, Rafael M. P. Teixeira, K. R. Pakuszewski, Wagner R. da Silva Neto, Juliana G. de Abrantes, Mirian Garcia-Fernandez, P. G. Pagliuso, C. Adriano, Claude Monney, Thorsten Schmitt, Eric C. Andrade, Fernando A. Garcia

Institutions: European Synchrotron Radiation Facility, Universidade de São Paulo, Université de Sherbrooke, Leipzig University, University of Surrey, Diamond Light Source, Universidade Estadual de Campinas (UNICAMP), University of Fribourg, Paul Scherrer Institute

Language: English

Topic: Iron-based superconductors research

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funders: Diamond Light Source, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico

Awards: G1192064772, Disentangling Electronic excitations in Hund Metals, G1384181827, Electron-Phonon Interactions in Rare-Earth Nickelates and Superconducting Cuprates, G221098106, Electronic correlations in quantum materials: inhomogeneities and frustration, G2588001846, G2800326885, G295657101, G3219658420, Mechanisms of stimulus-secretion coupling and exocytosis in normal B-cells and derived cell lines, G6030791512, G6438247056, Regionale Disparitäten und Spillovers - Fallbeispiele für den Raum St. Gallen, Charge and spin instabilities in unconventional superconductors, Correlated quantum materials, G7889526450, G8278318174, G8946531529

OpenAlex ID: W7123355876

FWCI:

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Cited by: 1

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