Defect structure and formation of defect complexes in Cu²⁺-modified metal oxides derived from a spin-Hamiltonian parameter analysis

Abstract

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Defect structure of the mixed ionic–electronic conducting Sr[Ti,Fe]Ox solid-solution system — Change in iron oxidation states and defect complexation

“…Examples include electrically neutral (Cu″ Ti − V O •• ) × in PbTiO 3 [32,33], [14,34] and in BaTiO 3 [35], as well as mutually compensating charged (Cu‴ Nb − V O ) • defect complexes in [K y Na 1 − y ]NbO 3 [36].…”

Defect‐driven evolution of piezoelectric and ferroelectric properties in CuSb2O6‐doped K0.5Na0.5NbO3 lead‐free ceramics

“…36 Besides, after the substitution of Cu 2+ for Nb 5+ , the oxygen vacancies are created to compensate charge neutrality in ceramics, giving an increase in the distance between B-site atoms and oxygen atoms, which also induces a weakening of B-O bond strength. Pure KNN ceramic has no EPR resonance peak because of its diamagnetic nature, while the ceramics with x=0.005-0.025 exhibit two magnetically inequivalent Cu 2+ centers with two spin-Hamiltonian parameters (g 1 [38][39][40] respectively. Figure 2A-F shows X-band EPR spectra of KNN-xCS ceramics, while the schematic view of DC1 and DC2 is plotted in Figure 2G.…”

“…Figure 2A-F shows X-band EPR spectra of KNN-xCS ceramics, while the schematic view of DC1 and DC2 is plotted in Figure 2G. Pure KNN ceramic has no EPR resonance peak because of its diamagnetic nature, while the ceramics with x=0.005-0.025 exhibit two magnetically inequivalent Cu 2+ centers with two spin-Hamiltonian [38][39][40] respectively. The incorporation reaction of CS in KNN ceramic can be illustrated by Equation (1):…”

Influence of the A/B Stoichiometry on Defect Structure, Sintering, and Microstructure in Undoped and Cu-Doped KNN

“…Such investigations are helpful when analyzing the amount of impurity ions or when determining the solubility limit of an ion in the KNN lattice. With respect to an analysis of the coordination of the copper functional centers, recently a semiempirical model has been developed to distinguish between different defect-structural models [18]. This model is based on an analysis of the relative values of electronic g-values versus copper hyperfine interaction.…”