The first-principles study for the novel optical properties of LiTi 2 O 4 , Li 4 Ti 5 O 12 , Li 2 Ti 2 O 4 and Li 7 Ti 5 O 12

The effects of oxygen in spinel oxide Li1+xTi2−xO4−δ thin films

“…First, the energy gap between e g and t 2g , named Δ e–t , is too small to be discernable in EELS. According to the band calculations, Δ e-t equals to 2.1 eV and 2.4 eV for the ideal structure LiTi 2 O 4 and Li 4 Ti 5 O 12 , respectively 36 . Moreover, four peaks were also observed in Li 7 Ti 5 O 12 , where Δ e-t equals to 1.8 eV 32 .…”

Lithium‐Battery Anode Gains Additional Functionality for Neuromorphic Computing through Metal–Insulator Phase Separation

“…However, the overall lithium content of Li 7 Ti 5 O 12 cannot change much upon phase separation, leading to less pronounced changes in the overall conductivity of the device, which remains orders of magnitude large than in the Li 4 Ti 5 O 12 device. Assuming as above that Li 7 Ti 5 O 12 has larger electric permittivity than Li 4 Ti 5 O 12 , which diverges in the metallic limit, the applied electric field will induce large asymmetries in the functional form of the chemical potential, as shown in Figure e. In particular, when the device is in the Li 7−ε Ti 5 O 12 state, the voltage required to turn the solution thermodynamically unstable and thus phase separate is smaller than in the case of Li 4+ε Ti 5 O 12 , as predicted by the simple spinodal estimate in Equation .…”

“…Here, we model resistive switching in LTO as a metal–insulator transition, controlled by electrically driven phase separation in a strain‐free binary solid. The permittivity of LTO increases with lithium concentration from ϵ i = ϵ (0) ≈ 1.5 ϵ 0 in the insulating phase at room temperature to diverging values in the metallic phase, ϵ ( c ) → ϵ m ≫ ϵ 0 as c → 1. At low concentration, the permittivity increases roughly in proportion to the population of Li + – e − polaron pairs and then grows nonlinearly with increasing lithium concentration.…”

How does the Li-distribution in the 16d sites determine the stability of A3(Li,Ti5)O12 (A = Li and Na)?

“…19 and 20. As for LTO and NTO, the electronic states have been investigated to design high-performance materials. [16][17][18][21][22][23][24][25][26][27][28][29][30][31] In a previous DFT study of LTO and newly discovered NTO, the electronic states and local atomic structures were examined. The O 2À anion in LTO and NTO can exibly move a distance from Ti, whereby it forms a coordinate bond with Ti and results in an analogous electronic state either for LTO or NTO with a local structural strain.…”