Research data supporting "Study of defect chemistry in the system La 2- Sr NiO 4+ by 17 O solid-state NMR spectroscopy and Ni K-edge XANES"

17O solid-state magic-angle spinning (MAS) NMR of 17O-enriched La2-xSrxNiO4+δ: broadband spin-echo spectra (pi/6 pulses) at x = 0, 0.1, 0.2, and 0.3; MATPASS spectra (pi/6 and pi/2 pulses) at x = 0, 0.1, 0.2, and 0.3; MATPASS spectra (pi/2 pulses) at x = 0.01, 0.025, and 0.05; MATPASS spectra (pi/6, pi/4, and pi/2 pulses) at x = 0.5, 0.75, and 1.0; selective (for Oi) spin-echo spectra at x = 0, 0.01, 0.025, 0.05, 0.1, 0.2, and 0.3. Raw powder XRD data of as-synthesised and 17O-enriched La2-xSrxNiO4+δ at x = 0.01, 0.025, 0.05, 0.1, 0.2, 0.3, 0.5, 0.75, and 1.0. Normalized Ni K-edge XANES data, i.e., absorption coefficients mu(E) and second derivatives of mu(E), of 17O-enriched La2-xSrxNiO4+δ at x = 0, 0.1, 0.2, 0.3, 0.5, 0.75, and 1.0.