High-temperature superparamagnetic behaviour of Cu-100-Co-x(x) systems containing Co particles in the nanometer range

Magnetisation curves of rapidly solidified Cu100 - xCox alloys (x = 5-25) have been measured at room temperature (T-o) up to 10 kOe. The temperature behaviour of the high-field magnetisation (H-o = 10 kOe) has been explored in the interval 290 K less than or equal to T less than or equal to 900 K. The comparison between the two measurements allows one to study the nature of magnetic interactions among nearly superparamagnetic Co particles. (C) 1999 Elsevier Science B.V. All rights reserved