STRUCTURAL AND MAGNETIC INVESTIGATIONS OF RAPIDLY QUENCHED AND ANNEALED TWO-PHASE NANOCRYSTALLINE Ni_(89)Hf_(11)

摘要

Rapidly solidification is an effective method to form nano-structured alloys. By means of this method one can obtain interfaces with differences in the chemical composition. We studied structural and magnetic properties of rapidly quenched and annealed nanocrystalline solids with different types of grain boundaries, but with the same average crystal size. Regarding these properties we could find no differences for these different kind of interfaces by diffraction and calorimetric methods. Low temperature magnetic measurements reveal compositional variations in the grain boundaries depending on the preparation methods. At 5 K we found in a quenched sample a hard magnetic grain boundary with paramagnetic behaviour at room temperature.