The TC(111) value

decreases from 0.394 to 0.357 as Li concentration increases from 2 to 10 at%. Conversely, the TC(200) value changes from 0.602 to 0.641, while the TC(220) value decreases from 0.393 to 0.360. It is well known that the AZD8931 supplier (200) plane of ionic rock salt materials is considered as a non-polar cleavage plane and is thermodynamically stable, and the most stable NiO termination has a surface Dinaciclib energy of 1.74 Jm−2. In contrast, the (111) plane is polar and unstable. Therefore, the (200) preferred orientation of L-NiO films can take on the better conductive properties and can resist electrical aging. In addition, the 2θ value of (111) diffraction peak is shifted from 37.22° to 37.38°

as Li content increases from 2 to 10 at %. It implies that the Li+ (0.6 Å) ions substitute the Ni2+ (0.69 Å) ions, and the smaller radius of Li+ ions would result in a decrease of lattice constant. Figure 3 XRD and GIXRD patterns of L-NiO films as a function of Li concentration. The Ni 2p 3/2 and O 1s XPS check details spectra of L-NiO films are shown in Figure 4 as a function of Li concentration. The deconvolution of Ni 2p 3/2 electron binding energy to Gaussian fit for NiO, Ni2O3, and Ni(OH)2 peaks is 854.0, 855.8, and 856.5 eV, respectively [12, 13]. For Ni 2p 3/2 electron binding energy, the intensities of Ni2+ and Ni3+ bonding states increase with Li concentration and lead to the decrease of resistivity for the L-NiO films. The Ni(OH)2 bonding state is caused by the adsorption of H2O, and its intensity increases with Li concentration. The tendency of Ni 2p 3/2 peak suggests that the

Ni3+ bonding state increases with Li concentration, as shown in Figure 4a,b,c. The O 1s XPS spectrum of L-NiO films is shown in Figure 4d,e,f. The intensity of O 1s peak increases as Li concentration increases, and the deconvolution of electron binding energy of Li2O (528.5 eV), NiO (529.9 eV), LiOH (531.1 eV), Ni2O3 Thalidomide (531.9 eV), Ni(OH)2 (531.9 eV), and adsorbed O or H2O (532.5 eV) exists in the L-NiO films [13–17]. The intensity of LiOH bonding state, which is caused by the combining Li+ and the OH− bonds of H2O, slightly increases with Li concentration. Compared with other electron binding energy, the binding energies for the Ni 2p 3/2 of Ni(OH)2 (856.2 eV) and the O 1s of LiOH (531.1 eV) are weaker in the modified SPM deposited L-NiO films. This result demonstrates that the non-polar (200) phase of L-NiO films increases with Li concentration (as shown in Figure 3) because the non-polar (200) phase exists with fewer dangling bonds, which cause the less binding probability to exist between in L-NiO films and water molecules. Figure 4 Deconvolution of Ni 2 p 3/2 and O 1 s XPS spectra of L-NiO films.