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Magnetic ground states and dynamics in manganese systems have been investigated for two different types of structure, the binary ~-Mnl.xMx and ternary RMn4AIs intermetallics where M represents cobalt or ruthenium and Ris a rare earth elemenVyttriumlscandium. For ~-Mn alloys containing cobalt impurities, astatic ground state of spin glass-like character has been stabilised for concentrations above 5% Co; there is an absence however of long range order in these systems, up to the highest measured concentration of 25at.% Co. The ~-Mnl.xRux alloys enter aspin glass-type state for all measured concentrations (above x=0.03), in conjunction with a higher-temperature transition to along range antiferromagnetically ordered state for x= 0.12, coexistent with the spin glass phase. These findings are evidenced by peaks in the muon spin relaxation rate, with acharacteristic stretched exponential relaxation function observed below the spin glass transition temperature. Further support is provided by susceptibility and polarized neutron measurements. Clear magnetic Bragg peaks in neutron powder diffraction data, in addition to specific heat anomalies, confirm the presence of the long-range ordered state in the ruthenium alloys. Neutron Iineshapes in anumber of samples of both series may also imply Non-Fermi liqUid scaling. These results are of particular significance in view of the fact that cobalt and ruthenium solutes are shown to substitute onto Site I of the ~-Mn crystal structure, as opposed to the more strongly magnetic Site II as for previously reported spin glass alloy systems, in which the impurity lifts magnetic frustration by removal of configurational degeneracy. Expansion appears to playa key role in ~-Mnl.xRux, with the introduction of ruthenium appearing to drive the system to an intermediate state between the weak itinerant and localized moment regimes. In the RMn4Als compounds, a range of interesting behaviour has been observed: this includes the first evidence of a magnetic phase transition in LaMn4Als, in the form of a peak in the low temperature J.lSR data together with weak Bragg peaks in polarized neutron measurements; PrMn4AIs has shown an oscillatory muon response, indicative of long range order in the Mn sublattice since inelastic neutron data shows Pr3+ to be in a singlet ground state. For systems with heavy rare earths (R = Er, Tb, Dy, Gd and Ho), interaction between the Rand Mn sublattices has been implied by J.lSR measurements, in which separate relaxation contributions have been ascribed to each species. For the RMn4Als with R= Y, Ce and Sc, aspin gap reported previously has been directly observed with inelastic neutron scattering. This is reflected in atwo-featured response in LaMn4Als, and may have its origins in aquasi-one dimensional Mn sublattice.

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Films of copper oxide were deposited on glass substrates by the reactive ion beam sputtering method. The amount of oxygen contained within was changed so that both metallic and insulating type films were obtained. Several basic measurements were attempted: comparison measurement by electron probe micro-analysis, CuO concentration measurements by electron spin resonance, optical measurements, magnetoresistance measurements and electrical measurements. The results showed that the metallic system could be well described by quantum corrections to the Boltzmann conductivity. There appeared to be both an electron-electron interaction correction and an electron-electron scattering mediated weak localisation, although in the latter the sign was negative due to spin-orbit scattering. The magnitude of the weak-localisation was shown to decrease as the metal insulator transition was approached. On the insulating side of the metal insulator transition the hopping type behaviour describes the conductivity, with both Mott hopping and hopping in a coulomb gap being seen. However, their relationship describes an unusual band structure around the fermi energy, where it is parabolic at higher energies and shows a flat bottom at lower energies. Composition was shown to be mixed, with both Cu, Cu₂O and CuO being seen for Cu₂O or below, nominal compositions. The films were also shown to contain un-reacted oxygen within. The metal insulator transition was found to occur at an oxygen concentration of 30.1±2 Atomic %, which is in broad agreement with that calculated from the minimum metallic conductivity.