1. In the application of nano ferric oxide in magnetic materials and magnetic recording materials

The size of magnetic particles as a magnetic recording unit must meet the following requirements: the length of particles should be smaller than the recording wavelength; The width of the particles (including possible lengths) should be much smaller than the recording depth; there should be as many magnetic particles as possible in a unit of recording volume. Nano fe2O3 has good magnetism and hardness. Oxygen magnetic materials mainly include soft magnetic iron oxide (α-Fe2O3) and magnetic recording iron oxide (γ-Fe2O3) . Because of its small size, single domain structure and high coercive force, magnetic nanoparticles can be used as magnetic recording materials to improve the signal-to-noise ratio and image quality. At present, the magnetic ultrafine particles used in the video tapes are generally needle-like particles of iron or iron oxide (such as needle-like γ-Fe2O3) .

2. The application of nano-ferric oxide in directional drug 

Targeted Medicine is one of the hotspots of current drug technology research. Under the action of external magnetic field, the drug can be moved to the lesion by the magnetic navigation of carrier-nanoparticle, so as to achieve the goal of directional therapy. This will not only greatly improve the efficiency of drugs, but also reduce the amount of drugs in other organs of the human body, so as to effectively avoid the drug in the focus of the effect of damage to other organs of the human body at the same time. Magnetic iron oxide nanoparticles have specific surface effect and magnetic effect. They are easy to be oriented and have no side effect on human body. They can be used as effective carrier for drug orientation. It is reported that magnetic iron oxide coated dextran nanoparticles can be used as gene carriers. Under acidic conditions, the nanoparticles exhibit DNA binding and resistance to DNASE-i digestion. The magnetic particles of 10-50 nm FE _ 3O _ 4 are coated with methacrylic acid with a size of 200 nm. These sub-micron particles carry proteins, antibodies and drugs that can be used in the diagnosis and treatment of cancer. This kind of local treatment effect is good, side effect is little, become the cancer treatment direction very likely.

3.Application of nanometer iron oxide in catalysts

Nano-sized iron oxide is a good catalyst because of its large specific surface area and obvious surface effect. Due to the small size, large volume percentage of surface, different bond and electron states and incomplete coordination of atoms on the surface, the active sites on the surface increase. The activity and selectivity of the catalyst made of nano-particles are higher than those of common catalysts, and the catalyst has long lifetime and is easy to operate. The hollow spheres made of nanometer α-Fe2O3were floated on the surface of wastewater containing organic compounds, and the degradation of organic compounds by sunlight could accelerate the process of wastewater treatment. The United States, Japan and other countries have adopted this method when dealing with the pollution caused by oil spills at sea. Nanometer α-Fe2O3 has been used as a catalyst for the oxidation, reduction and synthesis of polymers. Nanometer α-fe2O3 catalyst can increase the cracking rate of petroleum by 1-5 times, and the combustion rate of solid propellant made of α-fe2O3 as combustion catalyst can increase by 1-10 times than that of ordinary propellant, this is very advantageous for the manufacture of high-performance rockets and missiles