Abstract
Nanoparticles of FePt with diameter of 3 nm, even after heat treatment at 600 °C for 0.5 h in N
2 atmosphere, were fabricated by using mesopores of the MCM-41 molecular sieve as nano-reactors. An assembly of the FePt nanoparticles isolated by dielectric SiO
2 capping layer exhibited superparamagnetic behavior. The uniaxial magnetocrystalline anisotropic constant was estimated to 5.7
×
10
6 J/m
3 from the blocking temperature of 230 K.