Electronic Properties of Fully Strained La 1– x Sr x MnO 3 Thin Films Grown by Molecular Beam Epitaxy (0.15 ≤ x ≤ 0.45)

Sandeep Kumar Chaluvadi (1) , Vincent Polewczyk (1) , Aleksandr Yu Petrov (1) , Giovanni Vinai (1) , Luca Braglia (1) , Jose Manuel Diez (2) , Victor Pierron (3) , Paolo Perna (2) , Laurence Méchin (3) , Piero Torelli (1) , Pasquale Orgiani (1)

1 IOM - CNR Istituto Officina dei Materiali
2 Instituto IMDEA Nanociencia [Madrid]
3 Equipe Electronique - Laboratoire GREYC - UMR6072

The structural, electronic, and magnetic properties of Sr-holedoped epitaxial La 1−x Sr x MnO 3 (0.15 ≤ x ≤ 0.45) thin films deposited using the molecular beam epitaxy technique on 4°vicinal STO (001) substrates are probed by the combination of X-ray diffraction and various synchrotron-based spectroscopy techniques. The structural characterizations evidence a significant shift in the LSMO (002) peak to the higher diffraction angles owing to the increase in Sr doping concentrations in thin films. The nature of the LSMO Mn mixed-valence state was estimated from X-ray photoemission spectroscopy together with the relative changes in the Mn L 2,3 edges observed in X-ray absorption spectroscopy (XAS), both strongly affected by doping. CTM4XAS simulations at the XAS Mn L 2,3 edges reveal the combination of epitaxial strain, and different MnO 6 crystal field splitting give rise to a peak at ∼641 eV. The observed changes in the occupancy of the e g and the t 2g orbitals as well as their binding energy positions toward the Fermi level with hole doping are discussed. The room-temperature magnetic properties were probed at the end by circular dichroism.

Domaines: Electronique; Science des matériaux [cond-mat.mtrl-sci]

Sandeep Kumar Chaluvadi, Vincent Polewczyk, Aleksandr Yu Petrov, Giovanni Vinai, Luca Braglia, et al.. Electronic Properties of Fully Strained La 1– x Sr x MnO 3 Thin Films Grown by Molecular Beam Epitaxy (0.15 ≤ x ≤ 0.45). ACS Omega, 2022, ⟨10.1021/acsomega.1c06529⟩. ⟨hal-03650503⟩