Comparison of the Electric Noise Properties of Novel Superconductive Materials for Electronics Applications

The high transition temperature of recently discovered iron-based and electron-doped superconductors makes them interesting for advanced electronic applications. However, the complex conduction mechanisms responsible for the appearance of the superconducting state may strongly affect the devices' ultimate performances. The noise spectroscopy is a nondestructive technique that allows investigating in details the transport processes in action. The noise properties, in the normal state and in a wide temperature range, of thin films of iron-chalcogenides and pnictides, Sr1-xLaxCuO2 +/-delta infinite layer, and Nd1.85Ce0.15CuO4 electron-doped cuprates have been measured and compared. For each material, it has been possible to extract the value of the Hooge parameter, an empirical evaluation of the intrinsic noise level. The obtained results may be useful to set a lower limit in the electronic performances of devices based on these materials.