The influence of Ga$^+$-irradiation on the transport properties of mesoscopic conducting thin films

摘要

We studied the influence of 30keV Ga$^+$-ions -- commonly used in focused ionbeam (FIB) devices -- on the transport properties of thin crystalline graphiteflake, La$_{0.7}$Ca$_{0.3}$MnO$_3$ and Co thin films. The changes of theelectrical resistance were measured in-situ during irradiation and also thetemperature and magnetic field dependence before and after irradiation. Ourresults show that the transport properties of these materials strongly changeat Ga$^+$ fluences much below those used for patterning and ion beam induceddeposition (IBID), limiting seriously the use of FIB when the intrinsicproperties of the materials of interest are of importance. We present a methodthat can be used to protect the sample as well as to produce selectivelyirradiation-induced changes.