THERMODYNAMIC PROPERTIES OF NM-SIZED PD AND NI PARTICLES

With decreasing size the density of electronic states of a metal parti cle becomes different from that of the bulk. This significantly change s the behaviour of the thermodynamic properties of such a particle. We present specific heat and spin susceptibiblity measurements on a seri es of chemically synthesized Pd particles with diameters of 2.4-15 nm and magnetic measurements on a Ni colloid with an average diameter of about 2.8 nm. Pronounced size dependence of the electronic magnetic pr operties was found which is accompanied by only weak size dependence o f the electronic specific heat. This result can be understood in terms of a size-dependence of the Stoner enhancement factor, which only ent ers into the susceptibility and not into the specific heat.