Long range diffusion noise in platinum microwires with metallic adhesion layers

Voltage fluctuations of platinum wires hosted by silicon nitride beams were investigated. The authors considered four variants of the wires: three with an adhesion layer and one without an adhesion layer. They found that the presence of an adhesion layer changes the nature of the power spectrum which is 1∕f for wires with no adhesion layers and 1∕f3∕2 for wires with an adhesion layer. They attribute the value of the exponent α=3∕2 found in wires with adhesion layers to the long range diffusion of oxygen atoms along the interface between the adhesion layer and the platinum layer.