Journal Article

IMPULSE-2026-00136

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Phonons Reflect Dynamic Spin-State Order in LaCoO$_3$

Ivashko, A. ; Manjo, T. ; Kauth, M. ; Tymoshenko, Y. ; Merritt, A. ; Bohnen, K.-P. ; Heid, R. ; Merz, M. ; Eich, A. ; Castellan, J.-P. ; Ivanov, A. ; Schreiber, N. ; Zheng, H. ; Mitchell, J. F. ; Meven, M.MLZ* ; Park, J.MLZ* ; Ishikawa, D. ; Nakamura, Y. ; Baron, A. Q. R. ; Weber, F. (Corresponding author)

2026
APS College Park, Md.

Please use a persistent id in citations: doi:10.1103/tsw6-sdhk

Abstract: We investigate lattice dynamics in LaCoO3 using inelastic neutron and x-ray scattering over T=2−6⁢5⁢0  K, spanning the spin-state crossover at T1≈1⁢0⁢0  K and the insulator-metal transition at T2≈5⁢5⁢0  K. Comparison with quasiharmonic ab initio lattice-dynamical calculations helps reveal anomalous softening of a≈1⁢0−meV oxygen phonon, confined to the temperature interval T1≤T≤T2 and localized in momentum space at 𝐪SSO=(½,½,½)c. This wave vector is characteristic of the spin-state-ordering pattern originally proposed by Goodenough [An interpretation of the magnetic properties of the perovskite-type mixed crystals La1−x⁢Srx⁢CoO3−𝜆, J. Phys. Chem. Solids 6, 287 (1958)]. Our results provide momentum-resolved evidence for dynamic correlations of high-spin and low-spin Co3+ states characterized by 𝐪SSO=(½,½,½)c, demonstrating that phonons are sensitive probes of fluctuating spin-state correlations in LaCoO3.

Keyword(s): Basic research (1st) ; Condensed Matter Physics (2nd)

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Contributing Institute(s):

1. PUMA (PUMA)

Research Program(s):

1. DFG project G:(GEPRIS)460248799 - DAPHNE4NFDI - DAten aus PHoton- und Neutronen Experimenten für NFDI (DAPHNE4NFDI) (460248799) (460248799)

Experiment(s):

1. PUMA: Thermal three axes spectrometer (SR7)

Appears in the scientific report 2026

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Electronics and Telecommunications Collection ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOAP3 sponsored Journal ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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