A new form of TiO2 microspheres comprised of anatase/TiO2‐B ultrathin composite nanosheets has been synthesized successfully and used as Li‐ion storage electrode material. By comparison between samples obtained with different annealing temperatures, it is demonstrated that the anatase/TiO2‐B coherent interfaces may contribute additional lithium storage venues due to a favorable charge separation at the boundary between the two phases. The as‐prepared hierarchical nanostructures show capacities of 180 and 110 mAh g−1 after 1000 cycles at current densities of 3400 and 8500 mA g−1. The ultrathin nanosheet structure which provides short lithium diffusion length and high electrode/electrolyte contact area also accounts for the high capacity and long‐cycle stability.

Oil-dispersible α-NaYF4 spherical nanoparticles and β-NaYF4 hexagonal-shaped nanoplates were synthesized by the liquid−solid two-phase approach at different reaction temperatures. The TEM and FE-SEM images reveal that the nanoplates have a relatively narrow size distribution. In comparison with other methods, pure β-NaYF4 hexagonal-shaped nanoplates were prepared under a relatively mild condition. The nanoplates grew at the liquid−solid interface with slow crystallization rate, which may be preferable for achieving β-NaYF4.

It is of great difficulty to obtain deep-UV transparent materials with enhanced second harmonic generation (SHG), mainly limited by the theoretically poor transparency of these materials in the deep-UV spectral region. Here we report a new noncentrosymmetric, deep-UV transparent phosphate RbNaMgPO, which undergoes a thermo-induced reversible phase transition (at a high temperature of 723 K) and correspondingly an evident SHG enhancement up to ∼1.5 times. The phase transition is aroused by the twist of [PO] dimers with deviation from the P-O-P equilibrium positions. Theoretical analyses reveal that the enhanced SHG can be ascribed to the thermo-induced collective alignment of SHG-active [PO] dimers along the polar axis of high-temperature phase. This work provides an unprecedented physical routine (to SHG-enhanced materials) that is distinguished from the traditional one by chemical design and synthesis.

The Ca2+ and Ba2+ solubility on Nd3+ sites in new layered perovskite NdBaInO4 mixed oxide ionic and hole conductor and their effect on the oxide ion conductivity of NdBaInO4 were investigated. Among the alkaline earth metal cations Ca2+, Sr2+, and Ba2+, Ca2+ was shown to be the optimum acceptor–dopant for Nd3+ in NdBaInO4 showing the largest substitution for Nd3+ up to 20% and leading to oxide ion conductivities ∼3 × 10–4–1.3 × 10–3 s/cm within 600–800 °C on Nd0.8Ca0.2BaInO3.9 composition, exceeding the most-conducting Nd0.9Sr0.1BaInO3.95 in the Sr-doped NdBaInO4. Energetics of defect formation and oxygen vacancy migration in NdBaInO4 were computed through the atomistic static-lattice simulation. The solution energies of Ca2+/Sr2+/Ba2+ on the Nd3+ site in NdBaInO4 for creating the oxygen vacancies confirm the predominance of Ca2+ on the substitution for Nd3+ and enhancement of the oxygen vacancy conductivity over the larger Sr2+ and Ba2+. The electronic defect formation energies indicate that the p-type conduction in a high partial oxygen pressure range of the NdBaInO4-based materials is from the oxidation reaction forming the holes centered on O atoms. Both the static lattice and molecular dynamic simulations indicate two-dimensional oxygen vacancy migration within the perovskite slab boundaries for the acceptor-doped NdBaInO4. Molecular dynamic simulations on the Ca-doped NdBaInO4 specify two major vacancy migration events, respectively, via one intraslab path along the b axis and one interslab path along the c axis. These paths are composed by two terminal oxygen sites within the perovskite slab boundaries.

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