Application of magnetic nanomaterials

because the nanometer magnetic material has a variety of special magnetic properties, can be made into nanometer magnetic film (including magnetic multilayer film), nano magnetic line, nano powder (including magnetic powder block) and that a variety of forms such as magnetic materials, magnetic liquid in magnetic recording materials, magnetic liquid, permanent magnet material, magnetic material, biomedicine, radar absorbing material and other fields has a broad and important role. 1. In the application of magnetic recording materials in the world today is the age of information technology, the application of magnetic materials and information technology have great proportion, and nanoscale magnetic materials more created a new important applications, due to the magnetic nanoparticles with a single magnetic domain structure and the features of high coercive force, magnetic recording materials can use it to do improve the signal-to-noise ratio, improve the image quality, create conditions for high density magnetic storage. 2. Application in the field of magnetic liquids: magnetic liquids (also known as ferromagnetic fluids) are developed by utilizing the superparamagnetism of magnetic nanoparticles, which are stable colloidal substances formed by dispersing magnetic nanoparticles evenly and stably in a certain base carrier fluid through the coating of surfactants. This material has the fluidity of liquid and the magnetism of magnet. Its basic parameter is saturation magnetization intensity. Its size is mainly determined by the magnetic particles that make up the colloid. Magnetic liquid is widely used in rotary seal, such as disk drive dust seal, high vacuum rotary seal, and speaker shock absorption, damping devices, magnetic dyes, magnetic fuel, shift register display, magnetic liquid medicine, magnetic printing and other applications. 3. The applications for the permanent magnet material of permanent magnet materials, required magnetic stability is strong, keep the magnetic capability is strong, requiring permanent magnetic material with high maximum magnetic energy product (BH) Max], high residual magnetic flux density (Br) and high coercive force (HO), at the same time required quantity of the three magnetism to environmental conditions such as temperature has higher stability. In the actual situation, it is difficult to require (BH) Max], Br and HO to be relatively high, and one of the characteristics of nano magnetic materials is that single magnetic domain structure can be obtained under certain conditions, thus significantly improving the coercivity and permanent magnetic properties of permanent magnetic materials. Nanocrystalline permanent magnetic material can be used as power transformer, switching power transformer, filter, leakage protector, transformer and sensor, etc. For soft magnetic materials, it is generally required to have high initial permeability and saturation magnetization, chip retentivity, magnetic loss, broadband, etc. The results show that nano-permanent magnetic materials and nano-soft magnetic materials with superior properties can be made by selecting appropriate chemical components and technological conditions. For example, nanocrystalline magnetic films made by rf sputtering have been made into “three high” nano soft magnetic materials with high initial permeability, high saturation flux density and high Curie temperature. Nano-magnetic materials developed in recent years are developing along the direction of high frequency and multi-function, and their application fields will cover all aspects of the application of soft magnetic materials, such as power transformer, high frequency transformer, choke coil, current transformer, mutual inductor, magnetic shielding head and so on. Recently, nanocrystalline soft magnetic materials have been found to have giant magneto-impedance effect in high frequency field, which adds a colorful picture to its application as magnetic sensor. 5. The application of magnetic nanoparticles in the field of biomedicine to manufacture targeted delivery of medical drugs is a hot topic in pharmaceutical research. Due to the magnetic nanomaterials with small scale effect, good magnetic guide, physical compatibility, biodegradation and active functional groups etc, magnetic nanoparticles coated on the surface of polymer material, external and combined with protein, the containing protein and polymer magnetic nanoparticles as drug carrier, injected into the organism, in under the action of adscititious magnetic, through magnetic nanoparticles guidance make medicine more easily move to the lesion site, enhance its targeting of diseased tissue, improve efficacy, achieve the purpose of targeted therapy, thus maximum limit reduce the side effects of drugs, Selectively bruise or inhibit tumor cells. 6. With the development of military and civil science and technology such as radar, microwave communication, electronic countermeasures and environmental protection, the application of microwave absorbing materials is becoming more and more extensive. The basic principle is that when the microwave signal passes through the ferrite material, the electromagnetic energy is converted into other forms of energy (mainly thermal energy) and consumed. This kind of loss is mainly caused by the magnetic loss of ferrite and dielectric loss due to the special magnetic, infrared stealth and shielding effects of magnetic nanoparticles. The application of stealth has obvious advantages, improve the penetration ability and survival ability of various combat weapon platforms, can effectively inhibit the radiation of electromagnetic wave, leakage, improve the electromagnetic environment, improve the safety and confidentiality of the whole machine.

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