No abstract

Cluster deposited Pd films exhibit ferromagnetism in the temperature range from 1.8 to 400 K. The magnetization properties are found to be dependent on the film thickness. The varying morphology of the resulting Pd film with respect to thickness suggests that cluster size, deposition energy, and substrate type are crucial for the resulting film magnetization. This is demonstrated by the characteristic ferromagnetic hysteresis with the temperature dependent saturation magnetization, remanence, and coercivity of palladium nanocluster aggregates. The temperature dependence of the saturation magnetization, remanence, and coercivity of Pd nanoclusters were measured using an ultra-highsensitive magnetometer based on a superconducting quantum interference device, and the morphology of the samples was analyzed by tunneling electron microscopy.

Recent research has shown unconventional magnetic properties in nanosized gold systems. These effects have mostly been detected in functionalized gold nanoparticles as well as in gold nanocrystalline films. We demonstrate ferro-and superparamagnetic behaviour in assemblies of bare gold nanoclusters. This is demonstrated by the characteristic ferromagnetic hysteresis with the temperature dependent saturation magnetization, remanence and coercivity in aggregates of small clusters. The detected magnetization, is caused by the interaction between the separate clusters exhibiting an core-shell structure, and dependent on the total amount of gold confined in the samples. The behaviour is analogous to that of transition metal clusters.