Incorporation of the Ce.sup.3+./sup. activator ions in LaAlO.sub.3./sub. crystals: EPR and NMR study

0559410 - FZÚ 2023 RIV US eng J - Journal Article
Laguta, Valentyn - Buryi, Maksym - Pejchal, Jan - Uličná, K. - Římal, V. - Chlan, V. - Štěpánková, H. - Zagorodniy, Y. - Nikl, Martin
Incorporation of the Ce³⁺ activator ions in LaAlO₃ crystals: EPR and NMR study.
Journal of Solid State Chemistry. Roč. 313, Sep (2022), č. článku 123295. ISSN 0022-4596. E-ISSN 1095-726X
R&D Projects: GA ČR(CZ) GA20-12885S
Institutional support: RVO:68378271
Keywords : EPR and NMR * LaAlO₃:Ce * spin transfer * Fermi contact interaction
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.3, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.jssc.2022.123295

This work reports the results of EPR and NMR study of the Ce3þ incorporation in LaAlO3 single crystals grown by the micro-pulling-down method in the range of the Ce concentrations in the solid solution La1-xCexAlO3 from x ¼ 0.001 up to x ¼ 1.0. From EPR measurements, Ce3þ g tensor parameters were determined as a function of Ce concentration. The g tensor has an orthorhombic symmetry even in the trigonal phase (x < 0.1) suggesting that the incorporation of Ce at La site lowers the lattice symmetry near this ion. The local properties of the La1-xCexAlO3 crystals were further studied by 27Al and 139La high-resolution NMR measurements. It was found that 139La chemical shift has the Fermi contact interaction origin. It linearly increases with the Ce concentration from 0 ppm up to 165 ppm at x ¼ 0.5. Due to this strong Fermi contact interaction, separated peaks corresponding to different Ce–O–La spin transfer passways are resolved in the 139La NMR spectra.
Permanent Link: https://hdl.handle.net/11104/0333384