Quantitative electromechanical characterization of materials using conductive ceramic tips

The electromechanical properties of metallic and semiconductor materials are investigated in situ using hard, electrically conductive, vanadium carbide Berkovich tips fitted to a nanoindenter. We demonstrate that, for tip contact radii from 100 nm up to about 1 μμm, quantitative electrical data can be successfully obtained from the through-tip resistive measurements simultaneously with mechanical measurements. We outline a procedure for measuring the various resistive components of the electrical circuit that enables sample resistivity and other contact parameters to be evaluated with high precision during mechanical testing. The procedure requires that the tip-to-sample and sample-to-stage electrical contacts exhibit linear (ohmic) I–V characteristics. A gold electrical calibration standard is recommended, as well as a priori measurement of the tip area curves as a function of contact radius.