NO-Intercalation Properties of a Double-Layered Cuprate, La2-xBaxSrCu2O6. Dissociative Desorption of Intercalated NO

Abstract

The desorption process of nitric monoxide intercalated into the double layered cuprate, La1.4Ba0.6SrCu2O6, was studied by temperature programmed desorption-mass spectrometry (TPD-MS). The desorption profile consisted of NO (<600 °C), O2 (>600 °C) and N2 (>800 °C) peaks, the latter two implying dissociative desorption of the intercalated NO. Qualitative relations between NO uptake and each desorption suggests the presence of two different NO sites in the layer structure. One is the site bound to Ba, where NO is converted to NO2- ions, and produces a reversible NO desorption on heating (<620 °C). Another site is ascribable to an anion vacancy in the CuO5 pyramid layer, being occupied by NO strongly bonding to Cu. Instead of this NO ligand, lattice oxygens are eliminated as O2 above 600 °C. A further increase of temperature results in cleavage of the N−O bond and subsequent elimination of N2 while leaving the NO oxygen in the lattice. The dissociative NO desorption proceeds via the oxygen-exchange between the intercalated NO and the cuprate lattice.