Abstract
The magnetic and structural properties have been examined for pseudobinary compounds for many stoichiometries and solubility ranges in the phase diagrams defined by Y(Fe, Co) and Y(Co, Ni). Attempts have been made to account for the disappearance of certain phases in terms of atomic substitution and changes in the electron concentration. The magnetic behaviour is related to that of the alloys of the pure metals iron, cobalt and nickel; however a deep minimum is found to occur in the molecular moment in several stoichiometries near to the nickel compound. There is also a corresponding minimum in the exchange interaction strength. The observations may be understood in terms of an analysis involving the form of the density of states curves in these materials.