通过焦尔电阻加热,金属-金属氧化物核心-外结构的快速增长:形态,结构和发光特性
Juan Francisco Ramos-Justicia1, Ana Urbieta1, Paloma Fernández1
1Department of Materials Physics, Faculty of Physics, Complutense University of Madrid, 28040 Madrid, Spain.
Materials (Basel, Switzerland)
|January 11, 2024
概括
电阻加热合成核心外金属/金属氧化物复合材料. 氧化物层厚度和纳米结构的形成取决于金属和应用领域,有可能进行缺陷分析.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 固态化学 固态化学
背景情况:
- 金属/金属氧化物复合材料对于各种应用至关重要.
- 控制核心-外结构合成是定制材料特性的关键.
- 了解氧化物层形成机制对于材料设计至关重要.
研究的目的:
- 为了证明用于合成金属/金属氧化物核心外结构的电阻加热.
- 研究金属类型,时间,电流和外部场对氧化物层形成和形态学的影响.
- 描述合成复合材料的结构,化学和光学特性.
主要方法:
- 复合材料合成的电阻加热.
- 扫描电子显微镜 (SEM) 用于形态学和厚度分析.
- 对于元素组成的X射线光谱 (EDX).
- 用X射线衍射 (XRD) 和拉曼光谱进行结构分析.
- 光发光 (PL) 光谱用于缺陷和电子结构调查.
主要成果:
- 通过电阻加热成功合成了Zn/ZnO,Ti/TiO2和Ni/NiO核心外结构.
- 氧化物层的厚度因金属类型而异 (10-50微米).
- 独特的纳米结构 (针,镜,晶体) 在氧化物层上形成.
- 外部电场影响了纳米结构对齐和粒度边界形态.
- 鉴定证实了晶体,主要是石化氧化物阶段 (石,鲁,立方).
- 光发光揭示了氧气空缺和频段边缘附近的排放.
结论:
- 电阻加热是合成金属/金属氧化物核心外复合材料的有效方法.
- 材料特性,包括纳米结构形态和缺陷分布,可以通过控制合成参数来调整.
- 该研究提供了对这些先进材料的形成机制和缺陷特性的见解.
相关概念视频
01:17Theory 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
01:21Joule-Thomson Effect
4.0K
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...
4.0K
01:19Mechanism of heat transfer
1.2K
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
1.2K
01:14Mechanisms of Heat Transfer
329
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
329
01:20Mechanisms of Heat Transfer II
3.3K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
3.3K
01:14Mechanisms of Heat Transfer I
4.3K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
4.3K