Disorder and the Metal-Insulator Crossover in Pr$_{2-x}$Ce$_x$CuO$_{4-y}$

One of the outstanding issues in the electron doped cuprates is the role that oxygenation plays in the superconductivity and normal state properties. Oxygen addition can be considered both a doping and a disordering process. To disentangle these two effects, disorder can be introduced by irradiating the samples without altering doping. We report transport studies on optimal and underdoped Pr$_{2-x}$Ce$_x$CuO$_{4-y}$ films subject to proton irradiation and oxygenation. We establish a correlation between the static AFM and the metal-insulator crossover. Our separation of the disorder and doping effects also shed light on oxygen reduction effects in electron-doped cuprates. Supported by NSF grant DMR-0653535.