I tried to measure I - V characteristics for nanoparticles in the powder form, but I found it was not easy.
What are the suitable circumstances for an accurate measurement?
You may have a look at section 2.1 of the attached paper. We checked that the powders were Ohmic before deducing anything from the measurements.
Alain
In such cases usually powder compacts are investigated, but that is still not the "bulk" property. if you measure the complex impedance diagram, you may separate the bulk from the surface processes. You may also try to use the needle of a tunneling microscope on a single particle bu that requires a special apparatus.
You may have a look at section 2.1 of the attached paper. We checked that the powders were Ohmic before deducing anything from the measurements.
Alain
dear Ahmed, I think you will definitely find a very good methodology in Alain Celzard's paper - the conditions used - using a cleaned boro-silicate glass cylinder container to avoid cross-contamination, making solid pellets from the powders by well controlled compression, calibrating the dependence on the dimensions (surface area/volume ratio matter), etc... I recommend you follow his procedure and use his parameters (especially pressure applied to form the pellets and height of material in the tube ), and make yourself a calibration sample from one of the 17 carbon powders he characterized. By comparing your results to such a sample his, you should be able to attain to a good estimate of conductivity and what the error bar is between different labs.
In order to measure the I-V characteristics of a nanoparticle in poeder form, u can use an electrochemical workstation apparatus. It gives you accurate I-V value.
The most important point to get reproducible results is to define the geometry elaborately of the powder specimen. So you can compress the power into pellets, then you contact the pellet by foil electrodes coat them by silver epoxy such that you have electrodes having good contacts.
The measurement itself is staight forward where you can apply a voltage on the specimen and measure the current in it or vice verse.
To avoid the contact resistance of the electrodes you can use four electrode method where you pass a current in the specimen by the current electrodes and sense the voltage by the voltage electrodes.
There is many literature describing how to measure the powder I-V characteristics.
Best wishes
Please read my book (The American University Laboratories For Electrical Engineering Part 1)
You will find a nice way to get the I-V curve.
Keep in mind that any matierial has a resistance.
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