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Ellipsometric measurements have been made of optical properties of the heavy rare earth metals Gd, Tb, Dy, Ho, Er in the phonon energy range 0.35 eV to 2.5 eV and at certain temperatures between 20K and 300K corresponding to various magnetic phases of the metals. Rather diversive optical behaviour of the metals below the ordering temperature is interpreted in terms of exchange splitting of the levels near the Fermi level causing their reoccupation.

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.

Measurements have been made of the structural and magnetic properties of a series of pseudobinary compounds based on Gd3Co. The results have been interpreted in terms of the Neel theory of metamagnetism and the various exchange interaction coefficients have been obtained.

The magnetic and structural properties of the neodymium- dysprosium alloy system have been measured over the entire composition range. The crystal structures change from hcp to Sm type to dhcp arrangement with increasing neodymium concentration. Magnetization and initial susceptibility measurements suggest that the dhcp phase does not order magnetically. In the Sm phase antiferromagnetic behaviour is observed while the hcp alloys show a step ordering process. The Neel points follow a 2/3 power law variation with a reduced de Gennes function G given by the difference of the de Gennes functions for the two components of the alloy.

Measurements have been made of the magnetic ordering temperatures and spontaneous moments in the pseudobinary systems Y(Co, Ni)3 and Y2(Co, Ni)7. The results have been interpreted in terms of a rigid band model and it is suggested that the magnetic behaviour of YNi5 follows directly from the same band structure.

Spin echo measurements of the 59Co nuclear resonance in GdCo2 have revealed a rapid decay of the spin-echo amplitude with temperature up to 40 K followed by a further growth up to 79 K and subsequent decay above this temperature.