非中心对称的混合化物半导体La3Ga1.67(S1-Se) 7
Qichao Wu1, Arkadii Pominov1, Vidyanshu Mishra1
1Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
Inorganic chemistry
|May 7, 2025
概括
兰硫化化形成了一个完整的固体溶液,由于硫和原子的偏好,呈现出独特的结构变化和不同的光带间隙. 这些混合的石灰化物具有可调节的电子特性.
科学领域:
- 固态化学 固态化学
- 材料科学是一种材料科学.
- 晶体学 晶体学是指结晶学.
背景情况:
- 混合焦焦化物是含硫和的化合物,通常表现出独特的特性.
- 兰硫化 (La3Ga1.67(S1-xSex) 7) 是一种在电子和光学领域具有潜在应用的材料类.
- 了解这些固体解决方案中的结构属性关系对于材料设计至关重要.
研究的目的:
- 为了合成和表征混合素酸盐La3Ga1.67(S1-xSex) 7.一个完整的固体溶液.
- 研究不同硫和含量的结构演变和相位行为.
- 确定结构变化对这些材料光学和电子性能的影响.
主要方法:
- 在整个固体溶液范围 (x = 0.14个步骤) 中合成纯相样本.
- 粉末X射线衍射 (XRD) 用于相位识别和细胞参数的确定.
- 单晶XRD用于室温和低温 (100K) 的详细结构分析.
- 71Ga固态核磁共振 (NMR) 光谱用于地点分配.
- 光学光谱法用于确定实验光学带间隙.
主要成果:
- 形成了一个完整的固体溶液La3Ga1.67(S1-xSex) 7.
- 随着替代,细胞体积增加,而细胞参数显示出非单调的变化.
- 在室温下观察到非中心对称的六角结构 (P63),由于S/Se位置偏好,中间成员的结构变化异常.
- 在低温 (100K) 测定La3Ga1.67Se7的结构时,发现一个超级细胞 (P61) 的c轴翻了三倍,这表明它有扭曲作用以缓解键应变.
- 使用71Ga NMR确定了两个不同的Ga位点 (四面体和八面体).
- 光波段间隙从2.6 eV (La3Ga1.67S7) 一致性地减少到2.0 eV (La3Ga1.67Se7).
结论:
- 在La3Ga1.67(S1-xSex) 7固体溶液中的结构复杂性和不寻常的行为是由特定的S/Se地点占用和粘合要求驱动的.
- 观察到的结构扭曲,特别是在低温下,对于适应组成变化和减轻应变至关重要.
- 可调节的光学带间隙凸显了这些混合化物在光电子应用中的潜力.
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