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) h ave been measured at room temperature (T-o) up to 10 kOe. The temperature b ehaviour of the high-field magnetisation (H-o = 10 kOe) has been explored i n the interval 290 K less than or equal to T less than or equal to 900 K. T he comparison between the two measurements allows one to study the nature o f magnetic interactions among nearly superparamagnetic Co particles. (C) 19 99 Elsevier Science B.V. All rights reserved.