Fluctuations of the delay of the near-zone radiation field of injection heterolasers amplitude-modulated at high frequencies

Abstract

We have studied the high field susceptibility of nickel-platinum alloys in fields up to 150 kOe, at temperatures between 4.2 and 300 K. The high field susceptibility is analysed in the ferromagnetic and paramagnetic range by means of Arrott plots and Landau coefficients. The paramagnetic initial susceptibility follows a Curie-Weiss law, with a Curie constant independent of nickel concentration. The results are compared with those obtained for palladium-nickel alloys. We discuss the experimental data in the framework of recent theories on itinerant ferromagnetism.