Small
·
2021
·Vol. 18
·期 5
·2104460
·
IF 13.281
Yanan Huang,Jianguo Si,Shuai Lin,Hongyan Lv,Wenhai Song,Ranran Zhang,Xuan Luo,Wenjian Lu,Xuebin Zhu,Yuping Sun
3D anisotropic functional properties (such as magnetic, electrical, thermal, and optical properties, etc.) in a single material are not only beneficial to the multipurpose of a material, but also helpful to enrich the regulatory dimensionality of functional materials. Herein, a colossal 3D electrical anisotropy of layered MAB-phase MoAlB single crystal is introduced and dissected. Using high-temperature metal-solution method, high-quality MoAlB single crystals are obtained and a surprisingly strong out-of-plane ( σ a / σ b = 1.43 × 10 5 , at 2 K) and in-plane ( σ a / σ c = 12.12, at 2 K) electrical anisotropies are first observed. After a series of experimental and theoretical investigations, it is demonstrated that the 3D anisotropic crystal structure and chemical bond of MoAlB result in its 3D anisotropic phonon vibration and electronic structure, influence the corresponding electron-electron as well as electron-phonon interactions, and finally give rise to its colossal 3D anisotropy of electrical conductivity. This work experimentally and theoretically proves MoAlB single crystal possessing the 3D anisotropies of crystal structure, chemical bond, phonon vibration, electronic structure, and electrical transport, but also provides a promising platform for the future design of functionalized electronic devices as well as synthesis of new and large-sized in-plane anisotropic 2D material (MoBene).
研究领域:
凝聚态物理
·
材料科学
·
功能材料
·
晶体化学
·
纳米电子学
·
低维材料
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2022
·Vol. 11
·期 3
·2202195
·
IF 10.05
Xiaojing Li,Zilong Chen,Fuming Li,Fangfang Zhang,Zhihua Yang,Shilie Pan
A long-lasting challenge in ultraviolet (UV) nonlinear optical (NLO) materials design is to combine conflicting and harsh properties into one structure, including wide UV transparency, strong NLO efficiency, and moderate birefringence to realize phase-matching at short wavelength. A fluorine-directed material design strategy is adopted to accelerate the process of finding NLO materials with optimal performances. In this work, taking LiB 3 O 5 (LBO) as a maternal structure, one O atom with two F atoms is substituted and LiNaB 6 O 9 F 2 which possesses novel double interpenetrating 3 [B 6 O 9 F 2 ] ∞ networks and fluorine-directed optimal performances including enhanced birefringence and phase-matching capacity is successfully obtained. The perfect balance among deep-UV cutoff edge, large second-harmonic generation (SHG) response (1.1 × KDP), and moderate birefringence (0.067 at 1064 nm) of LiNaB 6 O 9 F 2 makes it a promising UV NLO crystal.
研究领域:
材料科学
·
晶体化学
·
非线性光学
·
功能材料
·
固体化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 11
·5615-5626
·
IF 11.9
Xiaohui Li,Xianyi Wei,Xiaoge Wang,Chenjie Lou,Wenda Zhang,Jungu Xu,Zhaoji Luo,Mingxue Tang,Sihao Deng,Lunhua He,Xianran Xing,Junliang Sun,Xiaojun Kuang
Melilite-type oxide ion conductors usually were observed in pure gallate compounds. Here a new mellite interstitial oxide ion conductor Ca2−xLaxGa2GeO7+x/2 (0 ≤ x ≤ 0.15) was developed by the substitution of La3+ for Ca2+ in Ca2Ga2GeO7 containing mixed GaO4/GeO4 tetrahedral layers. Neutron powder diffraction data indicated that the introduced interstitial oxide ions were accommodated in the distorted pentagonal rings, close to the coordination environment of (Ga2/Ge)O4 containing terminal oxygen. Defect formation energy calculations further reveal that the interstitial oxygen not only favors to approach the GaO4 tetrahedra, in agreement with studies of other pure gallate systems, but also is confined to the GeO4 tetrahedra. Bond-valence-energy landscape calculations and molecular dynamics simulations revealed that the interstitial oxide ions were transported among the pentagonal rings within the tetrahedral layers through a cooperative mechanism involving the synergistic knock-on motion between interstitial and framework oxygens. In Ca2Ga2GeO7, the La3+ substitution for Ca2+ only extended up to x = 0.15, which is much lower than those in the La–(Ca/Sr/Ba) based gallate mellites. The x = 0.15 composition resulted in oxide ion conductivities ∼2.79 × 10−5 S cm−1 to 1.68 × 10−3 S cm−1, with oxygen transport numbers of ∼92.65%, two orders of magnitude higher than that of the parent material. However, compared with pure gallate melilite interstitial oxide ion conductors with the same interstitial oxide ion concentrations, Ca1.85La0.15Ga2GeO7.075 has about one order of magnitude lower conductivity. The lower interstitial oxide ion concentration and conductivity in Ca2−xLaxGa2GeO7+x/2 reveal that although Ge4+ has similar chemical properties to the adjacent Ga3+, the subtle differences in size and the resultant covalent bonding ability make the mixed GaO4 and GeO4 tetrahedral layers in mellite unfavorable for accommodation and transportation of interstitial oxygens.
研究领域:
材料科学
·
固体离子学
·
能源材料
·
晶体化学
·
离子传输
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 21
·7143-7151
·
IF 4
Lu Liang,Xiaohui Li,Xiaoge Wang,Zhaoji Luo,Kun Lin,Qiang Li,Sihao Deng,Lunhua He,Xiaojun Kuang,Xianran Xing
Mixed electronic and oxide ionic conduction was enabled in digermanate-type La2−xCaxGe2O7−x/2 containing Ge3O10 chains and isolated GeO4 units by substitution of La3+ with Ca2+. The structure and solid solution limit of Ca doped La2Ge2O7 were studied by systematic experiments, including rotation electron diffraction (RED), X-ray diffraction (XRD) and neutron powder diffraction (NPD) experiments, etc. The preferred occupation of Ca2+ and oxygen vacancies was investigated by Rietveld analysis of the NPD data. The obtained conducting material La1.925Ca0.075Ge2O6.963 exhibits superior thermal stability and an order of magnitude improvement in conductivity compared to the parent La2Ge2O7 (∼9 × 10−5 S cm−1 at 1000 °C). BVEL calculations reveal that the oxygen vacancies were stabilized and transported within the framework of La2Ge2O7 by sharing oxygen and oxygen exchange between the adjacent Ge3O10 chains and GeO4 units, exhibiting a three-dimensional oxide ion transport nature.
研究领域:
无机化学
·
固态离子学
·
功能材料
·
结构化学
·
能源材料
·
晶体化学
✓ 已验证
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2024
·Vol. 36
·期 4
·109730
·
IF 9.4
Hongyuan Sha,Dongling Yang,Yanran Shang,Zujian Wang,Rongbing Su,Chao He,Xiaoming Yang,Xifa Long
Sulfates are always promising short-wave ultraviolet (UV) nonlinear optical (NLO) candidates, if their birefringence could be greatly improved. Here, in terms of the insufficient birefringence , the unity of heteroleptic tetrahedral groups and triangular ones was proposed and implemented. Thus, a new semi-organic crystal, [C(NH 2 ) 3 ]S 3 O 6 (G 2 S 3 O 6 ), was obtained, which is composed of [S 3 O 6 ] 2− and [C(NH 2 ) 3 ] + groups. It exhibits excellent optical properties with a short absorption cutoff edge of 218 nm, a strong NLO response of 1.4 × KH 2 PO 4 , and more especially, a large birefringence of 0.097@546 nm. This birefringence leap makes the G 2 S 3 O 6 crystal achieve a phase-matching behavior under a 532 nm laser. Thus, the synergy of [S 3 O 6 ] 2− and [C(NH 2 ) 3 ] + groups results in excellent optical performances. This finding opens a new horizon for exploring novel UV NLO crystals.
研究领域:
材料科学
·
光学工程
·
无机化学
·
晶体化学
·
非线性光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）