LAUSR

Magnetic and non-magnetic bilayer such as Permalloy (Py)\Cu is the basic unit in spintronic devices. To tune spin pumping effect of the bilayer system and enhance magnetic damping coefficient of Py, we fabricated Py\Cu1-xNdx bilayer films with capping (2nm) and buffer (5nm) layers of Ta deposited on silicon substrates at room temperature by magnetron sputtering. The Py thickness is about 10nm and Cu1-xNdx film thickness could be controlled from a couple of nm to a few tens of nm. There are several practical questions: 1) Based on the fact that Cu has almost no solubility in Nd, it is interesting to understand the microstructure of the Cu1-xNdx film. 2) XRD patterns do not show any peaks associated with Cu when x > 0. Is the Cu1-xNdx film amorphous? 3) The deposition rate was normally calibrated using pure materials. How accurate is the film thickness? When Cu and Nd were sputtered together, how could the film deposition rate be affected? 4) Ta buffer layer is amorphous, is there any effect of the buffer layer on Py microstructure?