%0 Journal Article %1 alarab2024nature %A Alarab, Fatima %A Hricovini, Karol %A Leikert, Berengar %A Richter, Christine %A Schmitt, Thorsten %A Sing, Michael %A Claessen, Ralph %A Minár, Ján %A Strocov, Vladimir N. %D 2024 %J APL Mater. %K a %N 1 %P 011118 %R 10.1063/5.0183140 %T Nature of the metallic and in-gap states in Ni-doped SrTiO$_3$ %U https://doi.org/10.1063/5.0183140 %V 12 %X Epitaxial thin films of SrTiO3(100) doped with 6% and 12% Ni are studied with resonant angle-resolved photoelectron spectroscopy at the Ti and Ni L2,3-edges. We find that the Ni doping shifts the valence band of n-doped pristine SrTiO3 toward the Fermi level (in the direction of p-doping) and reducing the bandgap. In the Ti t2g-derived mobile electron system (MES), the Ni doping depopulates the out-of-plane dxz/yz-derived bands, transforming the MES to two-dimensional and progressively reduces the electron density embedded in the in-plane dxy-derived bands as reflected in their Fermi momentum. Furthermore, the Ti and Ni L2,3-edge resonant photoemission is used to identify the Ni 3d impurity state in the vicinity of the valence-band maximum and decipher the full spectrum of the in-gap states originating from the Ni atoms, Ti atoms, and from their hybridized orbitals. Our experimental information about the dependence of the valence bands, MES, and in-gap states in Ni-doped SrTiO3 may help the development of this material toward its device applications associated with the reduced optical bandgap.

@article{alarab2024nature, abstract = {Epitaxial thin films of SrTiO3(100) doped with 6% and 12% Ni are studied with resonant angle-resolved photoelectron spectroscopy at the Ti and Ni L2,3-edges. We find that the Ni doping shifts the valence band of n-doped pristine SrTiO3 toward the Fermi level (in the direction of p-doping) and reducing the bandgap. In the Ti t2g-derived mobile electron system (MES), the Ni doping depopulates the out-of-plane dxz/yz-derived bands, transforming the MES to two-dimensional and progressively reduces the electron density embedded in the in-plane dxy-derived bands as reflected in their Fermi momentum. Furthermore, the Ti and Ni L2,3-edge resonant photoemission is used to identify the Ni 3d impurity state in the vicinity of the valence-band maximum and decipher the full spectrum of the in-gap states originating from the Ni atoms, Ti atoms, and from their hybridized orbitals. Our experimental information about the dependence of the valence bands, MES, and in-gap states in Ni-doped SrTiO3 may help the development of this material toward its device applications associated with the reduced optical bandgap.}, added-at = {2024-02-05T17:04:00.000+0100}, author = {Alarab, Fatima and Hricovini, Karol and Leikert, Berengar and Richter, Christine and Schmitt, Thorsten and Sing, Michael and Claessen, Ralph and Minár, Ján and Strocov, Vladimir N.}, biburl = {https://www.bibsonomy.org/bibtex/256955ca5d3cc0ddd7edc3db265b32187/ctqmat}, day = 22, doi = {10.1063/5.0183140}, interhash = {9445513bbb3021294f4e82736bcb745d}, intrahash = {56955ca5d3cc0ddd7edc3db265b32187}, issn = {2166532X}, journal = {APL Mater.}, keywords = {a}, month = {01}, number = 1, pages = 011118, timestamp = {2024-06-28T10:02:36.000+0200}, title = {Nature of the metallic and in-gap states in Ni-doped SrTiO$_{\mathbf{3}}$}, url = {https://doi.org/10.1063/5.0183140}, volume = 12, year = 2024 }