Magnetic Neutron Scattering Study of Nd$_{1.85}$Ce$_{0.15}$Cu$_{1-y}$M$_{y}$O$_{4}$ (M = Zn, Fe, Ni) Single Crystals

In order to arrive at a deeper understanding of the interplay between superconductivity and magnetism in the high-temperature superconductors, it is of interest to study the effects of impurity-doping on the copper site. A large body of work along these lines exists for several hole-doped materials, yet relatively little is known about the effects of such impurities on the prototypical electron-doped material (Nd,Ce)$_{2}$CuO$_{4+\delta }$. Paramagnetic dopants (Ni,Fe) have been shown to lower T$_{c}$ much more abruptly than non-magnetic ones (Zn). We have extended some of the previous work done on polycrystalline systems by growing large single crystals of Nd$_{1.85}$Ce$_{0.15}$Cu$_{1-y}$M$_{y}$O$_{4}$ (M = Zn, Fe, Ni) using the traveling-solvent floating-zone technique. In particular, we report our initial results for the in-plane charge transport measurements, as well as neutron scattering measurements of the N\'{e}el temperature T$_{N}$ and the two-dimensional spin correlation lengths for temperatures above T$_{N}$.