Excellent demo. I liked it very much. How this EIs was conducted? Whether the samples were dipped in brine for 24 hrs and 365 days and then normal EIS was conducted? Or some other method was used.
Thank you for the great question. Unfortunately, I cannot provide you very many details on these EIS data because they were collected by another researcher and submitted to me for use in my Advanced EIS Circuit Fitting webinar series. All I know is what the researcher told me, which is that the two EIS data sets I showed in this video were from a HDG sample with different immersion times (24 hours, then 360 hours). Beyond this information, I am not completely certain about other experimental parameters or details.
@@Pineresearch I appreciate your honest answer. I am using Biologic premium potentiostat. Though this instrument is excellent but I am missing wonderful webinars and online videos like yours of Pine research. And I am learning a lot from you guys. Thanks for sharing wonderful information on EIS.
@@growthinvestor1430 Thank you for your kind words! We strive to be a company that does both things - that is, make quality instruments, potentiostats, electrodes, software, etc., and also make good content like videos and webinars. I am glad you've found our content and hope you continue to enjoy it.
Hello! I wanna measure impedance for semiconductor metal oxide for use in electronics, I wanna use potentiostat. So, I was wondering how can I use it for such measurement and what is the best setup or conditions! If you have any information I would be grateful.
Measuring semiconductor properties electrochemically can be done in a way similar to almost any other electrochemistry experiment. It may depend on the form factor for your metal oxide. For example, if it is in a type of wafer or flat disk, you may need to connect it to an electrode holder and dip it into a vessel. If it is a metal oxide powder, you may need to cast a thin film onto a substrate like glassy carbon to perform electrochemical tests. Once you are able to figure out the manner for your working electrode, you will simply complete the setup with a counter and reference electrode, electrolyte, then you can perform EIS experiments. This is somewhat general, as I can only give general advice from the context of your question. If you have more specific questions, you can comment back here or join us on one of our weekly Livestreams here on TH-cam on Fridays.
I'm afraid I don't understand exactly what you mean. The role of the Nyquist plot is basically the same as the role of Bode plot, which is to say it is a visual representation of the EIS data. The software I use in this video demonstrates how you can view both Bode and Nyquist plots at the same time to help guide the circuit fit. Sometimes you may wish to adjust fit model and parameter values so the Nyquist plot looks best, sometimes you adjust so the Bode plot looks best. I believe I tried to be clear in this webinar, and every time I show these circuit fitting strategies, that those decisions are usually up to the researcher, and I am not trying to dictate what everybody must do all the time with their data. I hopefully try to provide some strategies and guidance, but the ultimate analysis and fitting is always up to the individual researcher. Please let me know if you are still confused by this, or perhaps you have a different hang-up about which you need further clarification.
The models are pretty much not correct, even if you can fit them well to the data. Steel is only in contact (exposed) with the solution when the polymer coating and zinc coating are artificially damaged, down to the steel. This could have been inquired about, from the originator of the data. Typically, however, one does not scratch the coating in EIS measurements on coated specimens (unlike in studies of delamination or filiform corrosion). So the title suggests something wrong, it is obviously not steel corrosion! Also, in my opinion, one does not need to assume any resistance/CPE between steel and zinc, since both metals can be assumed to have approximately the same electron conductivity. And in the end, calculating a corrosion rate on a coated sample may work mathematically, but it certainly does not make practical sense. I hope the critical remarks do not annoy you ;-) Best regards
Hello Dr. Heynz, thanks for your comment, and I appreciate that you clearly have some expertise in this area - most likely more than I did when I conducted this webinar. To try and be more clear based on your input, we've changed the title to specify it is "coated" steel, as hopefully this conveys a better message for the content. I genuinely enjoy and appreciate criticism and feedback like this, so absolutely no need to apologize for any annoyance. This is the essence of science - discussion and debate. In that spirit, please allow me to make a few comments in response to your salient feedback: First, generally speaking, I always do my best when conducting these kinds of webinars to admit that these data are submitted to me from researchers in the field, and I am only doing my best to illustrate possible EIS analyses. I have only the data and whatever pieces of additional information those researchers are at liberty to share with me, so it is possible I am lacking certain knowledge that would aid my analyses. Additionally, I have my own areas of expertise, and to be perfectly honest those do not always overlap ideally with the data used in my webinars. I always try to be very clear about this, and I also try to be honest that I may be wrong. I am fairly certain in this video I even mentioned, for example, that my analyses may not be perfectly valid, and even with respect to the steel-Zn interface that it may or may not be appropriate to use a Randles element. Second, I believe you are correct that there may not have been intentional scratches on the researcher's sample, but their sample was tested over extended hours and based on the information I received directly from the researcher, it is entirely possible the underlying layer(s) of steel and/or Zn could have become exposed after extended testing. Finally, regarding your comment on the mathematical analysis, I agree with you completely! Again, in the video I specifically mentioned this analysis may not be perfectly accurate. However, I find there to be great value in at least attempting to show how EIS data can be analyzed, first qualitatively, then quantitatively. It is certainly reasonable that these exact expressions may not be perfectly applicable to the system under study, but I still feel the value in demonstrating how EIS data might be used for further numerical analysis is quite high. I also performed a similar kind of quantitative analysis in an earlier webinar video on PEM fuel cells where I attempted to show how one might obtain diffusion coefficients from EIS data analysis. Again, I appreciate your feedback, and thank you for watching our TH-cam content! Dr. Neil Spinner
@@Pineresearch Hey Neil, thanks for the detailed and honest answer. I see it the same way as you do with the essence of science ;-) The really correct title would be "... coated galvanized steel corrosion" ;-). Galvanizing the steel will keep it from corroding for a very long time. Otherwise you would see red rust, usually white rust comes first when the zinc corrodes. But I think that was not the case here, the impedances at low frequency are still much too high. Overall, however, the impedance for a coating is very low here, so there is no good barrier effect. This is certainly not unusual for a biopolymer (possibly from development). Commercial coatings are well into the giga-ohm range. There it becomes very very difficult even for impedance measurements, but quite feasible. A short addition to the circuit diagram: by default, one uses a parallel circuit of a capacitance and a pore resistance and behind it the classic Rct+CPE. This is described very well in the literature. So, again, I hope this helps a little. Many greetings
Hello @@drheynz2755, I agree with your points. The impedance for a coating is indeed very low, but considering it's a biopolymeric film that is to be expected. I think I can incorporate all of this into the next EIS webinar involving some form of steel corrosion. Thank you!
Excellent demonstration. Thank you for sharing.
I am glad you enjoyed it, thanks for watching!
Exactly what I needed. I love you
Glad you enjoyed the video!
Excellent explaination.....
Glad you liked it!!
btw I am research scholar at Banaras Hindu University INDIA
Excellent demo. I liked it very much. How this EIs was conducted? Whether the samples were dipped in brine for 24 hrs and 365 days and then normal EIS was conducted? Or some other method was used.
Thank you for the great question. Unfortunately, I cannot provide you very many details on these EIS data because they were collected by another researcher and submitted to me for use in my Advanced EIS Circuit Fitting webinar series. All I know is what the researcher told me, which is that the two EIS data sets I showed in this video were from a HDG sample with different immersion times (24 hours, then 360 hours). Beyond this information, I am not completely certain about other experimental parameters or details.
@@Pineresearch I appreciate your honest answer. I am using Biologic premium potentiostat. Though this instrument is excellent but I am missing wonderful webinars and online videos like yours of Pine research. And I am learning a lot from you guys. Thanks for sharing wonderful information on EIS.
@@growthinvestor1430 Thank you for your kind words! We strive to be a company that does both things - that is, make quality instruments, potentiostats, electrodes, software, etc., and also make good content like videos and webinars. I am glad you've found our content and hope you continue to enjoy it.
Hello! I wanna measure impedance for semiconductor metal oxide for use in electronics, I wanna use potentiostat. So, I was wondering how can I use it for such measurement and what is the best setup or conditions! If you have any information I would be grateful.
Measuring semiconductor properties electrochemically can be done in a way similar to almost any other electrochemistry experiment. It may depend on the form factor for your metal oxide. For example, if it is in a type of wafer or flat disk, you may need to connect it to an electrode holder and dip it into a vessel. If it is a metal oxide powder, you may need to cast a thin film onto a substrate like glassy carbon to perform electrochemical tests. Once you are able to figure out the manner for your working electrode, you will simply complete the setup with a counter and reference electrode, electrolyte, then you can perform EIS experiments.
This is somewhat general, as I can only give general advice from the context of your question. If you have more specific questions, you can comment back here or join us on one of our weekly Livestreams here on TH-cam on Fridays.
i didn't understand the purpose from nyquist plot like what the role of this plot in corrosion study ?
I'm afraid I don't understand exactly what you mean. The role of the Nyquist plot is basically the same as the role of Bode plot, which is to say it is a visual representation of the EIS data. The software I use in this video demonstrates how you can view both Bode and Nyquist plots at the same time to help guide the circuit fit. Sometimes you may wish to adjust fit model and parameter values so the Nyquist plot looks best, sometimes you adjust so the Bode plot looks best. I believe I tried to be clear in this webinar, and every time I show these circuit fitting strategies, that those decisions are usually up to the researcher, and I am not trying to dictate what everybody must do all the time with their data. I hopefully try to provide some strategies and guidance, but the ultimate analysis and fitting is always up to the individual researcher.
Please let me know if you are still confused by this, or perhaps you have a different hang-up about which you need further clarification.
The models are pretty much not correct, even if you can fit them well to the data. Steel is only in contact (exposed) with the solution when the polymer coating and zinc coating are artificially damaged, down to the steel. This could have been inquired about, from the originator of the data. Typically, however, one does not scratch the coating in EIS measurements on coated specimens (unlike in studies of delamination or filiform corrosion). So the title suggests something wrong, it is obviously not steel corrosion! Also, in my opinion, one does not need to assume any resistance/CPE between steel and zinc, since both metals can be assumed to have approximately the same electron conductivity. And in the end, calculating a corrosion rate on a coated sample may work mathematically, but it certainly does not make practical sense. I hope the critical remarks do not annoy you ;-) Best regards
Hello Dr. Heynz, thanks for your comment, and I appreciate that you clearly have some expertise in this area - most likely more than I did when I conducted this webinar. To try and be more clear based on your input, we've changed the title to specify it is "coated" steel, as hopefully this conveys a better message for the content.
I genuinely enjoy and appreciate criticism and feedback like this, so absolutely no need to apologize for any annoyance. This is the essence of science - discussion and debate. In that spirit, please allow me to make a few comments in response to your salient feedback:
First, generally speaking, I always do my best when conducting these kinds of webinars to admit that these data are submitted to me from researchers in the field, and I am only doing my best to illustrate possible EIS analyses. I have only the data and whatever pieces of additional information those researchers are at liberty to share with me, so it is possible I am lacking certain knowledge that would aid my analyses. Additionally, I have my own areas of expertise, and to be perfectly honest those do not always overlap ideally with the data used in my webinars. I always try to be very clear about this, and I also try to be honest that I may be wrong. I am fairly certain in this video I even mentioned, for example, that my analyses may not be perfectly valid, and even with respect to the steel-Zn interface that it may or may not be appropriate to use a Randles element.
Second, I believe you are correct that there may not have been intentional scratches on the researcher's sample, but their sample was tested over extended hours and based on the information I received directly from the researcher, it is entirely possible the underlying layer(s) of steel and/or Zn could have become exposed after extended testing.
Finally, regarding your comment on the mathematical analysis, I agree with you completely! Again, in the video I specifically mentioned this analysis may not be perfectly accurate. However, I find there to be great value in at least attempting to show how EIS data can be analyzed, first qualitatively, then quantitatively. It is certainly reasonable that these exact expressions may not be perfectly applicable to the system under study, but I still feel the value in demonstrating how EIS data might be used for further numerical analysis is quite high. I also performed a similar kind of quantitative analysis in an earlier webinar video on PEM fuel cells where I attempted to show how one might obtain diffusion coefficients from EIS data analysis.
Again, I appreciate your feedback, and thank you for watching our TH-cam content!
Dr. Neil Spinner
@@Pineresearch Hey Neil, thanks for the detailed and honest answer. I see it the same way as you do with the essence of science ;-)
The really correct title would be "... coated galvanized steel corrosion" ;-). Galvanizing the steel will keep it from corroding for a very long time. Otherwise you would see red rust, usually white rust comes first when the zinc corrodes. But I think that was not the case here, the impedances at low frequency are still much too high. Overall, however, the impedance for a coating is very low here, so there is no good barrier effect. This is certainly not unusual for a biopolymer (possibly from development). Commercial coatings are well into the giga-ohm range. There it becomes very very difficult even for impedance measurements, but quite feasible. A short addition to the circuit diagram: by default, one uses a parallel circuit of a capacitance and a pore resistance and behind it the classic Rct+CPE. This is described very well in the literature. So, again, I hope this helps a little. Many greetings
Hello @@drheynz2755, I agree with your points. The impedance for a coating is indeed very low, but considering it's a biopolymeric film that is to be expected. I think I can incorporate all of this into the next EIS webinar involving some form of steel corrosion. Thank you!