Bonded thin cylinder magnets using Sm-Fe-N anisotropic powder
Anisotropic bonded Sm-Fe-N thin cylinder magnets have been developed by an injection-molding technology using unsaturated polyester resin, because thin and high-performance magnets are needed in order to downsize the motor. A special point for forming was a control of the rate of shrinkage. A multioriented cylinder magnet of 0.8 mm thickness was made by an insertion forming an aluminum column of 18.4 mm diameter and 18 mm height. A radial-oriented cylinder magnet of 15 mm outer diameter, 16 mm height, and 0.5 mm thickness was also made.
Sm/sub 2/Fe/sub 17/N/sub 3/ magnet powder made by using reduction and diffusion method
High performance Sm/sub 2/Fe/sub 17/N/sub 3/ magnet powder is developed by a reduction and diffusion method. Typical remanence, coercivity and maximum energy product obtained are 1.40 T, 1.13 T and 323 kJ/m/sup 3/, respectively. Decreasing samarium content, oxygen content and the amount of /spl alpha/-Fe are found to be the important factors to realize high energy product.
Photoinduced spin-state transition of Co3+ in the layered perovskite manganite thin film
The photoinduced effect, at different temperatures, on layered perovskite manganite La1.2Sr1.8Mn1.8Co0.2O7 thin film deposited on a SrTiO3(100) substrate has been studied using a He–Ne laser (632.8 nm) with the power of output 25 mW at low temperatures. The electrical transport and magnetic properties of the film are investigated systematically in the temperature region from 20 to 300 K. The resistance shows a significant decrease at low temperatures (T<90 K) under laser irradiation, which can be interpreted in terms of the spin-state transition of Co3+ ions. The magnetic field combined with the laser is also used to detect the photoinduced effect of the spin-glass state. The time dependence of the metastable system under several applied fields was also discussed. The system has the ability to keep a persistent memory of the magnetic history imprinted in its zero-field resistance.