马格尼利相中的氧气空隙及其对热电性能的影响
Zhou Guan1, Chuangshi Feng1, Hongquan Song2
1Songshan Lake Materials Laboratory, Dongguan 523808, China.
Nanomaterials (Basel, Switzerland)
|May 13, 2025
概括
这项研究合成了单相马格尼利相 (TinO2n-1) 用于能源应用. 这些材料表现出良好的热电性能,峰值zT值在1100 K时达到0.18.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 能源转换材料 能源转换材料
背景情况:
- 马格尼利相 (TinO2n-1) 由于其高电导率和热稳定性,对能源应用具有前景.
- 了解结构-属性关系对于优化它们的性能至关重要.
研究的目的:
- 使用碳热还原和热压烧结合成单相马格尼利相 (Ti4O7,Ti5O9,Ti6O11) 的方法.
- 为了研究相位演变,微观结构和热电性质之间的相关性.
- 分析影响热电性能的因素,例如氧气空缺和剪切表面密度.
主要方法:
- 纳米尺寸的鲁TiO2的碳热还原.
- 热压烧结用于散装材料制造.
- 同步射线X射线衍射 (SXRD) 和扫描电子显微镜 (SEM) 用于结构和微观结构分析.
- 热电性质测量从300-1100 K.进行测量.
- 单一抛物线带 (SPB) 模型用于理论计算.
主要成果:
- 成功合成了单相Ti4O7,Ti5O9和Ti6O11,它们的相对密度很高 (>97%).
- 在1100K时观察到0.17,0.18和0.14的峰值热电功率 (zT) 值,分别为Ti4O7,Ti5O9和Ti6O11.
- 与氧气空隙度和剪切表面密度相关的热电性能,影响载体度和晶格导热率.
结论:
- 使用所述的方法,可以有效地准备单相马格尼利相.
- 热电性能受到物质内在特性 (如氧空位和剪切表面密度) 的显著影响.
- 这些发现为设计基于马格尼利相的先进热电材料提供了洞察力.
更多相关视频
04:09Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics
Published on: August 30, 2024
275
11:07Synthesis of Non-uniformly Pr-doped SrTiO3 Ceramics and Their Thermoelectric Properties
Published on: August 15, 2015
9.8K
相关概念视频
Joule-Thomson Effect
2.5K
The Joule-Thomson effect, also known as the Joule-Kelvin effect, describes the temperature change of a fluid when it is forced through a valve or porous plug while keeping it in a thermally insulated environment. This experiment is called a throttling process. This is an important effect widely used in refrigeration and the liquefaction of gases.
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
2.5K
Thermodynamic Potentials
744
Thermodynamic potentials are state functions that are extremely useful in analyzing a thermodynamic system. They have dimensions of energy. The four important thermodynamic potentials are internal energy, enthalpy, Helmholtz free energy, and Gibbs free energy. These thermodynamic potentials can be expressed using two of the following variables: pressure, volume, temperature, and entropy. These two variables are expressed as the rate of change of the thermodynamic potential with respect to other...
744
Thermodynamics: Activity Coefficient
1.2K
Activity is the measure of the effective concentration of the species in solution. It can be expressed as the product of the molar concentration of the species and its activity coefficient. The activity coefficient is a dimensionless quantity and depends on the total ionic strength of the solution.
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
1.2K
Thermodynamics: Chemical Potential and Activity
825
The effective concentration of a species in a solution can be expressed precisely in terms of its activity. Activity considers the effect of electrolytes present in the vicinity of the species of interest and depends on the ionic strength of the solution. The activity of a species is expressed as the product of molar concentration and the activity coefficient of the species.
The thermodynamic equilibrium constant is more accurately defined in terms of activity rather than concentration.
The thermodynamic equilibrium constant is more accurately defined in terms of activity rather than concentration.
825
Path Between Thermodynamics States
2.9K
Consider the two thermodynamic processes involving an ideal gas that are represented by paths AC and ABC in Figure 1:
2.9K
Theory of Metallic Conduction
1.3K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
1.3K
