Evidence of the oxygen vacancies-induced room temperature ferromagnetism in multiferroic Co-doped LiNbO3 films

Facile synthesis of novel lithium β-diketonate glyme adducts: the effect of molecular engineering on the thermal properties

“…require the availability of LiNbO 3 in thin film form. To this aim various techniques have been applied such as capillary liquid epitaxial technique, 12 RF-magnetron sputtering, 13 spin-coating 14 and metal-organic chemical vapour deposition (MOCVD).…”

Regulating Crystal Structure and Atomic Arrangement in Single-Component Metal Oxides through Electrochemical Conversion for Efficient Overall Water Splitting

“…X-ray photoelectron spectroscopy (XPS) measurements were carried out to investigate the elemental states in FeO x /NF before and after electrochemical conversion reaction. The Li 1s and Na 1s signals located at ≈55.5 eV and ≈1069.7 eV, respectively, confirm the intercalation of Li and Na ions into FeO x /NF-Li and FeO x /NF-Na during electrochemical conversion reaction (Figure a,b). − As shown in Figure c, the Fe 2p 3/2 and Fe 2p 1/2 peaks located at ≈724.6 eV and ≈711.3 eV could be deconvoluted into two components assigned to Fe 3+ and Fe 2+ . , Notably, the molar ratio of Fe 2+ /Fe 3+ for FeO x /NF-Li (FeO x /NF-Na) is higher than that for FeO x /NF, which is probably attributed to the electron donation from the created oxygen vacancies (Vo) during electrochemical conversion reaction . As observed in the XPS O 1s spectrum of FeO x /NF (Figure d), the peaks with binding energies at 530.1, 531.4, 532.9, and 534.2 eV are attributed to the metal–oxygen (M–O), metal-hydroxyls (M–OH), Vo, and physically adsorbed water, respectively. − One will note that the content of Vo increases in the order of FeO x /NF < FeO x /NF-Na < FeO x /NF-Li, indicating that more Vo are introduced into FeO x /NF by Li intercalation than by Na intercalation.…”

Lithium Niobate Single Crystals and Powders Reviewed—Part II

“…Figure 11 shows the plots of magnetic moment per transition metal-cation of LN doped with Fe (1-LN:Fe), Mn (2-LN:Mn), V (7-LN:V), as well as four different systems of LN doped with Co (labeled as 3-LN:Co, 4-LN:Co, 5-LN:Co, and 6-LN:Co). All samples were prepared as layers by different methods [190,192,198,[202][203][204][205]. As can be seen, for 2-LN:Mn and 7-LN:V, the AMM increases as the x increases until reaching a maximum; after that, the AMM begins to decrease as x increases.…”

“…However, recently some efforts have been put on as-obtained coarse LN particles that show ferromagnetism at RT. On an investigation carried out in 2018 by our group, it was found that the generation of oxygen vacancies-by thermal treatment in reducing atmospheres: thermal treatment in a reducing atmosphere (TTRA)-at the surfaces of LN:Fe powders is a mechanism that favors RT ferromagnetism at low doping concentrations of 0.44%, 0.89%, 1.47%, and 2.20% by mass of Fe2O3 (labeled as nLN:Fe-0.44-R, nLN:Fe-0.89-R, nLN:Fe-1.47-R, nLN:Fe-2.20- There is a tendency in what respects doped-LN to study single-crystal and polycrystal thin films, in comparison to polycrystalline powders; further results on the Fe impurity and reports on the doping with Co, Cu, and V-based on similar studies to those above just described-can be consulted in the literature [198,[202][203][204][205][206][207]. However, recently some efforts have been put on as-obtained coarse LN particles that show ferromagnetism at RT.…”

“…As previously explained, the AMM decrease is mainly associated with the formation of secondary phases or lattice damage due to excess dopant, which destroys the magnetic coupling. There is a tendency in what respects doped-LN to study single-crystal and polycrystal thin films, in comparison to polycrystalline powders; further results on the Fe impurity and reports on the doping with Co, Cu, and V-based on similar studies to those above just described-can be consulted in the literature [198,[202][203][204][205][206][207]. However, recently some efforts have been put on as-obtained coarse LN particles that show ferromagnetism at RT.…”