Crystal growth and structure refinement of NaCuO2 by X-ray and neutron diffraction

Possible relationship between Cu-NQR frequencies and Cu valence states in CuO2-planes for high-T c superconductors

“…While in CuO the Cu ions are in a valence state close to 2+, in NaCuO 2 they are in a valence state close to 3+ [19]. For layered cuprates the formal valence sum V i of Cu has been estimated using the empirical formula [2,22]:…”

Transport properties and lithium insertion study in the p-type semi-conductors AgCuO2 and AgCu0.5Mn0.5O2

“…This high conductivity and low Seebeck coefficient is accounted by an electronic delocalized state driven by the 4d XANES/EXAFS investigations, who reported the existence of oxidation states higher than +1 and lower than +3 within Ag and Cu sites, respectively [36]. Therefore, the silver in AgCuO 2 is more oxidized which may also explain the enhanced air stability of AgCuO 2 whereas the localized trivalent copper LiCuO 2 , NaCuO 2 and KCuO 2 are all water sensitive [8,[42][43][44].…”

Effects of impurity Na+ ions on the structural and magnetic properties of Ni–Zn–Cu ferrite powders: An improvement for chemical coprecipitation method

“…After careful analysis, the impurity diffraction peaks in Fig. 1(f-j) can be attributed to Na compounds, especially the NaCu-O compounds [13,14], but it is hard to determine their real crystalline structure. Obviously, it is the impurity Na þ ions that result in the formation of multi-phase structure in O specimens.…”