LOCAL VERSUS LONG-RANGE MAGNETIC-ORDERING IN LANI5-XFEX

Magnetic properties of LaNi5-xFex has been investigated in magnetic fi elds up to 15 kG, at temperatures T>1.5 K. Magnetic clustering effects are evidenced, and characterized by the local Fe composition, the con centration and size of the magnetic clusters. The analysis of the data leads to a good understanding of the complex magnetic phase diagram o f LaNi5-xFex in the whole range of compositions 0.05<x<1.2. In particu lar the onset of itinerant ferromagnetism takes place at x almost-equa l-to 0.5 in addition to the ferromagnetism of iron moments which takes place at the magnetic percolation threshold x almost-equal-to 0.35 +/ - 0.05.