Reduction of particle size modifies magnetic properties of materials

Iranian researchers from Isfahan University of Technology modified the properties of a magnetic material by using nanotechnology, which has many applications in various industries.
Barium ferrite is a magnetic material that is used in the production of permanent magnets, magnetic sorption environment and microwave adsorbents. Size, structure, and magnetic properties of the material highly depend on the production conditions and the nature of the raw material used in the production process.
According to the supervisor of the research, Dr. Parviz Kameli, effort was made in this research to investigate the produced barium ferrite nanoparticles and the effect of re-cooking temperature on magnetic properties of the final product.
In the present studies, various methods, including sol-gel or hydrothermal methods, have usually been used for the production of barium ferrite nanoparticles. But in this research, the nanoparticles have been produced through co-precipitation method in the presence of high concentration of hydroxide ions and low process temperature.
Taking into consideration the low temperature of the production process, reduction in energy consumption and increase in the production rate of the final product are among the important results of the research.
FE-SEM images taken from the structure of the product show that the re-cooking temperature is an important parameter in controlling the size of particle diameter from nanometric to micrometric scale, to the extent that as temperature increases from 90 to 1200°C, the size of nanoparticles changes from a few nanometers to micrometers.
On the other hand, magnetic properties of the nanoparticles increase as the re-cooking temperature increases. In this report, the best temperature was reported to be 900°C to obtain magnetic properties and the optimum particle size.