Exploring a route to induce ferromagnetism on Sr3Sn2O7 by co-doping with non-Jahn-Teller-distorted Mn3+ and La3+ cations

Blasco, J. ; Cuartero, V. (Universidad de Zaragoza) ; Lafuerza, S. ; Gracia, D. ; Puente-Orench, I. ; Rodríguez-Velamazán, J.A. ; Herrero-Martín, J. ; Torchio, R. ; Mathon, O. ; Subías, G.

Resumen: We here explore a route to induce a ferromagnetic ground state on the Ruddlesden-Popper phases Sr3-xLaxSn2-xMnxO7 replacing Sn by Mn up to x = 1.25. Samples with low Mn concentration (x ≤ 0.1) adopt the polar A21am space group, consistent with previously reported ferroelectric behavior. For higher Mn concentrations (x ≥ 0.25) the samples adopt the centrosymmetric space group Amam due to the suppression of specific rotational modes. X-ray absorption spectroscopy confirmed the presence of a Mn3+ ion in all samples though it is not Jahn-Teller distorted. An undistorted MnO6 octahedral local structure is reported instead, with Debye-Waller factors for the Mn-O bond length increasing as Mn content does, due to the disorder induced in the Sn/Mn sublattice and the rising of rumpling distortions (expansion of the perovskite bilayer coupled with shrinkage of the rock salt layer). All the Sr3-xLaxSn2-xMnxO7 samples exhibit ferromagnetic correlations. While Mn³ ⁺ cations in low Mn-content samples (x ≤ 0.25) agree with spin-only contributions, higher doping levels deviate from this interpretation, possibly due to the enhancement of magnetic interactions. At 5 K, all samples exhibit spontaneous magnetization which increases with Mn content, but the Mn³ ⁺ magnetic sublattice is not fully polarized. Neutron diffraction confirmed the absence of long-range magnetic order and AC susceptibility analysis indicates a cluster-glass magnetic state due to structural disorder and competing interactions. Compared to simple perovskites, our results indicate that the rock salt layer plays a key role in suppressing long-range ferromagnetic order, making it particularly challenging to achieve multiferroic behavior by doping hybrid improper ferroelectrics with magnetic cations.

Idioma: Inglés

DOI: 10.1016/j.jallcom.2025.185048

Año: 2025

Publicado en: JOURNAL OF ALLOYS AND COMPOUNDS 1048 (2025), 185048 [9 pp.]
ISSN: 0925-8388

Financiación: info:eu-repo/grantAgreement/ES/DGA/E11-23R
Financiación: info:eu-repo/grantAgreement/ES/DGA/E12-23R
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2021-124734OB-C21
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2021-124734OB-C22
Financiación: info:eu-repo/grantAgreement/ES/MICIU/CEX2023-001286-S

Tipo y forma: Article (Published version)

Área (Departamento): Área Cienc.Mater. Ingen.Metal. (Dpto. Ciencia Tecnol.Mater.Fl.)