Hafnium Oxide

Hafnium Oxide powder is a white crystalline powder composed of hafnium and oxygen elements, with high melting point, high hardness, good chemical stability, high dielectric constant, etc. It is widely used in semiconductors, optics, high temperature materials, nuclear industry and many other fields.

Characteristics

Chemical formula: HfO₂

Molar mass: 210.49 g/mol

Appearance: usually off-white or white powder

Density: 9.68 g/cm³

Melting point: 2758°C

Boiling point: 5400°C;

Band gap: 5.3 to 5.7 eV, an electrical insulator;

Refractive index: high in the near-ultraviolet to mid-infrared region, e.g. 2.13 at 1700 nm;

Coefficient of thermal expansion: low

Thermal conductivity: 1.1 W/m-K

Young’s modulus: 57 GPa

Electrical resistivity: high, typically 9 × 10⁹ Ω-m.

High chemical stability: it does not react with water at room temperature and is insoluble, but it can react with strong acids and bases such as concentrated sulphuric acid, and it will slowly dissolve in hydrofluoric acid to generate hafnium fluoride acid radical ions; it will react with chlorine to generate hafnium tetrachloride at high temperature and in the presence of graphite or carbon tetrachloride.

Applications

Semiconductor field:

Gate insulating layer material: in the semiconductor industry, due to hafnium oxide has a high dielectric constant, wide bandgap and other characteristics, it is likely to replace the current silicon-based integrated circuits, the core device of the metal oxide semiconductor field effect tube (MOSFET) gate insulating layer silicon dioxide (SiO₂), to help solve the bottleneck in the development of traditional SiO₂/Si structure in the semiconductor devices to reduce the size of the development bottlenecks, can improve the performance and integration of semiconductor devices. performance and integration of semiconductor devices.

Memory devices: Hafnium oxide is ferroelectric, which means it can store data for long periods of time even in the absence of a power supply, and has great potential for applications in new non-volatile storage technologies, such as for the preparation of ferroelectric random access memory (FeRAM).

Optical field:

Optical coating materials: Hafnium Oxide can be used to prepare optical coatings, which can increase the transparency of light on the surface of lenses, glass and other objects, reduce glare, and have good anti-reflection, anti-wear, anti-ultraviolet or computer radiation. Commonly used in the production of UV film, anti-reflective film or high reflective film and UV – near infrared multilayer film.

Laser materials: Hafnium Oxide can be used in optical components and devices related to near-ultraviolet lasers, playing an important role in laser generation, transmission and modulation.

High-temperature ceramics:

Refractory materials: hafnium oxide has a high melting point and high hardness, and still maintains good stability at high temperatures, can be used in the manufacture of high-temperature furnaces, crucibles and other high-temperature refractory equipment, as well as in the ceramic thermal barrier coatings, which can effectively protect the substrate material from erosion in high-temperature environments.

Ceramic cutting tools: Hafnium Oxide can be added to ceramic materials as an additive or reinforcing phase to improve the hardness, abrasion resistance and cutting performance of ceramic cutting tools, making them suitable for cutting and processing materials with high hardness.

Catalysts: Hafnium Oxide can be used as a catalyst or catalyst carrier to promote the reaction and improve the reaction efficiency and selectivity in some chemical reactions.

Other fields:

Anti-Radioactive Coatings: Due to its blocking and protective effect on radioactive substances, it can be used to prepare anti-radioactive coatings, which are applied in nuclear industry and other places with radioactive environment.

Biomedical field: It has certain application prospects in biomedicine, for example, it can be used to make oral restoration materials.

Aerospace field: its excellent performance makes it can be used in the aerospace field to manufacture high temperature resistant, wear-resistant parts and coatings.