Spin fluctuations in a very weak itinerant ferromagnet: Y₄Co₃

The authors present a detailed comparison of the data on magnetic susceptibility and resistivity as a function of temperature with the predictions of the theory of weak itinerant ferromagnetism which takes spin fluctuations into account. The agreement is good provided the authors decompose the paramagnetic susceptibility into the Curie-Weiss and the temperature-independent parts. They also compare the results obtained for Y4Co3 with those for other weak ferromagnets. The Stoner enhancement factor and the molecular field at T=0 are determined. The authors also draw some conclusions about the electronic structure of Y4Co3 (or Y9Co7) above the superconducting transition temperature.