I used gold sputtering (to make electrode contacts) in Ca doped LaInO3 samples for AC conductivity measurement from room temperature to 800C. Does it interfere with the conductivity response of my sample?
I do not know what LaInO3 samples are like (insulator, semiconductor ?..). I agree with Jea that Cr adhesion layer before Au layer is a good thing (It works on sapphire, silica glas, Si monocrystal (doped, undoped). In all these case , the electrode geometry is well defined.
Multilayer metal electrode systems can be considered in most cases as a single metal layer, so in this respect, there is no problem in standard Electrical Impedance Spectroscopy experiment. However, it might be that the Cr layer might alter the electrochemical potential of pure gold layer facing your sample, in which case your depletion/accumulation layer (if present) will be altered. The amount will depend on the difference in the respective electrochemical potentials (elchpot of Cr/Au and elchpot of your sample). My gues is that this difference is about few tenths of eV (~0.1-0.2 eV). The best way is :
1. To measure the impedance for your system with two different thicknesses (doubling the thickness will double the low frequency real part of impedance, while halving the real part of the measured capacitance) If this is all you see, then you are not measuring sample-electrode interface and there is no problem.
2. If 1. is false, the low frequencies should reveal your metal electrode-system interface and in this region of frequencies you should see whether Cr adhesion layer affects this part of the impedance sopectra.
With regards
Petr
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