Size Dependence of the Curie Temperature of Separate Nickel Particles Studied by Interference Electron Microscopy

Interference electron microscopy was applied to measure the size dependence of the Curie temperature of small nickel particles. Nickel films consisting of particles of different sizes and distances between them were studied. We found a decrease of the Curie temperature with decreasing particle size for particles smaller than about 100 nm. The decay of the Curie temperature is stronger for particles being well separated from other particles, whereas the decay is much less pronounced in the case of small distances between the particles. This observation can be explained by interparticle interaction.