> Current-voltage characteristics were recorded using 2614b Keithley SourceMeter and 2182A Keithley Nanovoltmeter, using either 4-terminal or van der Pauw geometry. Due to strong inhomogeneity of the samples, their current-voltage characteristics show a broad variation of response, with resistance ranging many orders of magnitude, and V-I curves showing signatures of switching, hysteresis, and nonlinearity. Samples appear to be brittle as well. Often, samples crack and break down during measurements, when high current (> 50 mA) was applied, or during mounting due to even slight mechanical vibration.
> Overall, at this stage, we can conclude that although the synthesis of LK-99 shows XRD features similar to the reported, and EDX data confirm their elemental composition, but no signatures of superconductivity are visible
> Overall, at this stage, we can conclude that although the synthesis of LK-99 shows XRD features similar to the reported, and EDX data confirm their elemental composition, but no signatures of superconductivity are visible