TY - JOUR
T1 - Low-energy orbital excitations in strained LaCoO3 films
AU - Wang, Ru Pan
AU - Geessinck, Jaap
AU - Elnaggar, Hebatalla
AU - Birkhölzer, Yorick A.
AU - Tomiyasu, Keisuke
AU - Okamoto, Jun
AU - Liu, Boyang
AU - Du, Chao Hung
AU - Huang, Di Jing
AU - Koster, Gertjan
AU - De Groot, Frank M.F.
PY - 2019/10/31
Y1 - 2019/10/31
N2 - We present 90 meV resolved Co 2p3d resonant inelastic x-ray scattering linear dichroism spectra of strained LaCoO3 films and a LaCoO3 single crystal. A polarization-dependent low-energy excitation is observed at ∼0.2eV on the tensile-strained LaCoO3/SrTiO3 film, while it is not observed in either bulk LaCoO3 or the compressive-strained LaCoO3/LaAlO3 film. Guided by cluster calculations, we are able to distinguish the spin-state manifolds close to their transition point of Co3+ ions in LaCoO3 systems. Through a polarization analysis, we show that the spin state can easily flip from a low-spin A1g1 state in an octahedral symmetry to the high-spin B2g5 or Eg5 states with a small tetragonal distortion. A mixture of spin states suggests that the high-spin Co3+ plays an important role in long-range ferromagnetic order on both tensile- and compressive-strained LaCoO3 films.
AB - We present 90 meV resolved Co 2p3d resonant inelastic x-ray scattering linear dichroism spectra of strained LaCoO3 films and a LaCoO3 single crystal. A polarization-dependent low-energy excitation is observed at ∼0.2eV on the tensile-strained LaCoO3/SrTiO3 film, while it is not observed in either bulk LaCoO3 or the compressive-strained LaCoO3/LaAlO3 film. Guided by cluster calculations, we are able to distinguish the spin-state manifolds close to their transition point of Co3+ ions in LaCoO3 systems. Through a polarization analysis, we show that the spin state can easily flip from a low-spin A1g1 state in an octahedral symmetry to the high-spin B2g5 or Eg5 states with a small tetragonal distortion. A mixture of spin states suggests that the high-spin Co3+ plays an important role in long-range ferromagnetic order on both tensile- and compressive-strained LaCoO3 films.
UR - http://www.scopus.com/inward/record.url?scp=85074998924&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.100.165148
DO - 10.1103/PhysRevB.100.165148
M3 - Article
AN - SCOPUS:85074998924
SN - 2469-9950
VL - 100
JO - Physical review B: Covering condensed matter and materials physics
JF - Physical review B: Covering condensed matter and materials physics
IS - 16
M1 - 165148
ER -