当地结构和物种驱动的UO22+ → Sm3+ 能量转移用于Li2B4O7中的增强发光
Annu Balhara1,2, Santosh K Gupta1,2, Brindaban Modak2,3
1Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Inorganic chemistry
|November 30, 2023
概括
在四酸盐 (Li2B4O7) 中对 (Sm3+) 排放的乌拉尼尔敏感化是通过代实现的. 这项研究揭示了影响能源转移效率的结构变化,达到70.5%.
科学领域:
- 固态化学和材料科学 固态化学和材料科学
- 发光和光谱学 发光和光谱学
- 计算材料科学 计算材料科学
背景情况:
- 四酸 (Li2B4O7) 添加了Sm3+,是一种有前途的材料.
- 了解局部结构和能量传递机制对于优化发光特性至关重要.
研究的目的:
- 为了研究编的Li2B4O7中Sm3+排放的乌拉尼尔敏感化:Sm3+.
- 阐明结构变化和能量转移途径.
- 为了将结构变化与发光效率和热稳定性相关联.
主要方法:
- 基于同步的扩展X射线吸收细结构 (EXAFS) 谱学,以确定乌拉尼尔物种和局部结构.
- 密度函数理论 (DFT) 计算以评估缺陷形成能量和能量转移可行性.
- 时间分辨率光发光 (PL) 谱学用于研究能量转移效率和温度依赖的光发光.
主要成果:
- 乌拉尼尔离子 (U(VI)) 被确定为五边形 (UO7) 和六边形 (UO8) 双金字塔,其协调数影响Sm3+的局部结构.
- 与Sm3+和合作降低了空位的形成能量,促进了UO2+赤道协调.
- 从UO22+到Sm3+的高效能量转移 (ET) 得到证实,在0.5mol%的密封样本中,效率为70.5%.
- 乌兰排放振动特征的红色转移与赤道协调增加相关,并且在UO8物种类型中观察到更高的ET概率.
- 一个高能量的屏障 (Ea ≈ 4027 cm-1) 确定了Sm3+排放的热火.
结论:
- 在Li2B4O7中,乌拉尼尔物种化和局部结构变化显著调节Sm3+的发光和能量传输效率.
- 六角双金字塔式乌拉尼尔物种化 (UO8) 有利于更高的能量转移概率.
- 这项研究提供了通过控制的结构修改和理解能量传输动态来优化性能的见解.
更多相关视频
09:09A Facile Synthetic Method to Obtain Bismuth Oxyiodide Microspheres Highly Functional for the Photocatalytic Processes of Water Depuration
Published on: March 29, 2019
7.8K
07:24Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
17.2K
相关概念视频
01:14Photoluminescence: Applications
405
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
405
02:54Trends in Lattice Energy: Ion Size and Charge
23.9K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
23.9K
02:16Resonance and Hybrid Structures
16.9K
According to the theory of resonance, if two or more Lewis structures with the same arrangement of atoms can be written for a molecule, ion, or radical, the actual distribution of electrons is an average of that shown by the various Lewis structures.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
16.9K
01:23Photoluminescence: Fluorescence and Phosphorescence
2.1K
Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds.
A pair of electrons in a...
A pair of electrons in a...
2.1K
03:02Colors and Magnetism
11.7K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.7K
02:58Crystal Field Theory - Octahedral Complexes
26.6K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.6K