Lattice spacings and domain sizes of room-temperature epitaxial Li x Ni 1−x O (0 ≤ x ≤ 0.48) thin films grown on ultra-smooth sapphire substrates

Lattice distortion and electronic structure of magnesium-doped nickel oxide epitaxial thin films

“…Because of the phase transformation from the rhombohedral structure with random Li + occupation to the hexagonal structure with the preferred occupation of the two cationic sites in Li x Ni 1−x O when x > 0.31 [11,12], the lattice parameter of Li 0.48 Ni 0.52 O bulk decreases by 2.3% [12]. This was confirmed by the reduction of r Ni-O by 2.5%, based on the measured d film 111 of the Li 0.48 Ni 0.52 O thin film [32]. In contrast, Mg x Ni 1−x O offers higher Mg solubility with lower lattice distortion.…”

“…When compared with the Li x Ni 1−x O epitaxial films that were studied in our previous work [32], the lattice distortion of the Mg x Ni 1−x O films is much smaller. Because of the phase transformation from the rhombohedral structure with random Li + occupation to the hexagonal structure with the preferred occupation of the two cationic sites in Li x Ni 1−x O when x > 0.31 [11,12], the lattice parameter of Li 0.48 Ni 0.52 O bulk decreases by 2.3% [12].…”

Sub-nanoscale nanoimprint fabrication of atomically stepped glassy substrates of silicate glass and acryl polymer

“…These nanostructured sapphire molds exhibit the unique surface morphology having about 0.2-nm-high straight steps and about 100-nm-wide ultrasmooth terraces [19,20]. The atomically stepped sapphire wafers were also found to be useful as growing substrates of high-quality thin films at low temperatures [21][22][23][24] as well as atomic force microscopy (AFM) stages observing the steric shape of organic molecules adhered to their surfaces [25,26]. In the present article, we have briefly reviewed the sub-nanoscale nanoimprint fabrication of atomically stepped glassy substrates of soda-lime silicate glasses and PMMA polymers by employing the atomically stepped sapphire molds in the thermal nanoimprint.…”

Atomic disorder of Li0.5Ni0.5O thin films caused by Li doping: estimation from X-ray Debye–Waller factors

“…Li x Ni 1Àx O thin films were epitaxically grown on ultra-smooth sapphire (0001) substrates (Yoshimoto et al, 1995) by RT pulsed laser deposition. Details of the deposition conditions have been reported elsewhere (Shiraishi et al, 2010;Yang et al, 2014). The compositions of NiO thin films containing large amounts of Li grown at RT were determined using inductively coupled plasma atomic emission spectrometry (Shimadzu ICPS-8100).…”

“…Li x Ni 1Àx O has attracted considerable attention recently as a potential material for high-performance electrochromic devices (Moulki et al, 2012), UV detectors (Ohta et al, 2003) and gas sensors (Garduno-Wilches & Alonso, 2013). Recently, cubic type NiO thin films with (111) orientation containing large amounts of Li (up to 50 mol%) were epitaxically grown on ultra-smooth sapphire (0001) substrates by roomtemperature (RT) pulsed laser deposition (Shiraishi et al, 2010;Yang et al, 2014). The ultra-smooth sapphire substrate used in this work has an atomic 'step and terrace' structure on its surface, which consists of atomically flat terraces comprising single oxygen layers separated by periodic atomic steps with 0.22 nm height corresponding to the oxygen layer spacing along the c axis.…”