@@Bilim-Teknoloji-Tarih Professor I had a question regarding my Bi2Se3 sample synthesised ontop of a sapphire substrate. I am modelling the sample in GenX however I'm unsure what is the chemical composition of the oxidation layer ontop of the bismuth selenide . Do you have a method to determine this? Finally, is there a method to determine if an interface layer has formed in between the sample and substrate using XRR analysis?
Dear@@muneebahmed1848. You can determine the chemical composition of the oxidation layer on bismuth selenide using the XPS method. Alternatively, you can get this information from XRR simulations. Watch the video from 1:34:30. You can find an example there. With regard to the formation of any interface layer between sample and substrate, XRR can help you. But to get reliable results, you should pay close attention to other parameters. It requires experience and can take a lot of time. But in principle it may be possible for expert users of the XRR method.
@@Bilim-Teknoloji-Tarih thank you for your help professor. I had one last question, following your example in the video if I had two oxides in one layer for example Bi2O3 and SeO2 would they combine as Bi2O5Se?
thank you so much Prof. Akdogen for this wonderful lecture. few quick questions from the part of thickness determination. you mentioned that in a relatively thicker film, more oscillations will be there because of a greater number of planes in the film. in that case how do you explain d as thickness of the film and not the interplanar spacing. second, since the measurement is done by sweeping the incident angle. how it is different from GIXRD.
You are welcome Ateed Ahmad. For the thickness determination you may watch from 1:08:59. The idea is the same for "d" determination. In this case "d" means the distance between top and bottom surfaces of the film.
Dear Mienph Lee. You can get the thickness, roughnes and electron densities of each layer by simulating XRR data. There are free and commercial XRR simulation programs based on Parrat formalism. This information is also discussed in the lecture video. Best wishes.
@@Bilim-Teknoloji-TarihIf we manually input thickness, roughnes and electron densities of each layer in the XRR simulation programs then we get the simulation XRR curve. Thank for your kind answer.
@@mingfengli8187 You are welcome. Some programs automatically calculate the parameters (thickness, roughness, density) after entering layers and their nominal values.
Hello dr. How can I Communication with you . I am want to ask you about Infrared (( Portion of Reflected and Transmitted Radiation: Fresnel Equations ))
Hi. I've been using this animation in my lectures for the last ten years. But I don't remember where I got it from or who gave it to me. Maybe a friend or a student gave it to me. I would be very happy if you know the source and share it with me. Best wishes.
Sir, I have a very thin Pt layer (nominal thickness is 1nm) deposited by magnetron sputtering on Si wafer. the thickness of the native oxide layer of Si is similar to the deposited Pt layer. however, the native oxide layer thickness changes every time when try to fit the curve. could yu briefly explain the reason? Thanks you so much!
Hi MemetTursun. First, you need to define the layers with the correct electron densities. That is, without changing the electron densities of the Si, SiO2 and Pt layers, the table values should be entered as they are. You can get them from webelements.com. And try to fit the XRR curve with nominal thicknesses. If it does not work, you can manipulate the roughnesses. If the simulation still does not fit the data, you can slightly increase the Pt density and play with roughnesses. But not too much. Additionally, you should get the best fit around the critical angle (before and after). If this first part of the XRR curve is not well-fitted, the fit parameters (thickness, roughness, density) may be incorrect. I wish you success.
@@Bilim-Teknoloji-Tarih dear Professor Akdogan, Thank you for your quick reply! I will try the way you mentioned. Also, I have other one question: when fit the curves for different Pt thickness, the resulted SiO2 layer thickness is different for different sample, in spite of very good fit for different sample. what do you think the reason might be? Thank you very much !
![BLACK BAG - Official Trailer [HD] - Only in Theaters March 14](http://i.ytimg.com/vi/Du0Xp8WX_7I/mqdefault.jpg)
Best introductory video of XRR on youtube. Deserves more views!
Thank you Muneeb Ahmed. Enjoy the videos. Best wishes.
@@Bilim-Teknoloji-Tarih Professor I had a question regarding my Bi2Se3 sample synthesised ontop of a sapphire substrate. I am modelling the sample in GenX however I'm unsure what is the chemical composition of the oxidation layer ontop of the bismuth selenide . Do you have a method to determine this?
Finally, is there a method to determine if an interface layer has formed in between the sample and substrate using XRR analysis?
Dear@@muneebahmed1848. You can determine the chemical composition of the oxidation layer on bismuth selenide using the XPS method. Alternatively, you can get this information from XRR simulations. Watch the video from 1:34:30. You can find an example there.
With regard to the formation of any interface layer between sample and substrate, XRR can help you. But to get reliable results, you should pay close attention to other parameters. It requires experience and can take a lot of time. But in principle it may be possible for expert users of the XRR method.
@@Bilim-Teknoloji-Tarih thank you for your help professor. I had one last question, following your example in the video if I had two oxides in one layer for example Bi2O3 and SeO2 would they combine as Bi2O5Se?
Dear@@muneebahmed1848 . I can only tell you that the electron density will change if there is the formation of other oxide phases.
Best explanation of XRR I have seen. Thanks a lot sir.
You are welcome Alisha. Enjoy the lectures. Best wishes.
Very nice video, well explained Prof. Numan. Prof Numan could you please suggest some free software's used for simulation?
Very informative lecture on xrr. Thank you so much.
You are welcome. Enjoy the videos.
thank you so much Prof. Akdogen for this wonderful lecture.
few quick questions
from the part of thickness determination.
you mentioned that in a relatively thicker film, more oscillations will be there because of a greater number of planes in the film.
in that case how do you explain d as thickness of the film and not the interplanar spacing.
second, since the measurement is done by sweeping the incident angle.
how it is different from GIXRD.
You are welcome Ateed Ahmad. For the thickness determination you may watch from 1:08:59. The idea is the same for "d" determination. In this case "d" means the distance between top and bottom surfaces of the film.
Çok teşekkürler.. çok açıklayıcı bir anlatımdı.
Rica ederim. Çok selamlar.
prof,I'd like to know how we measure CoO's and Fe's thickness separately?Thank you!
Dear Mienph Lee. You can get the thickness, roughnes and electron densities of each layer by simulating XRR data. There are free and commercial XRR simulation programs based on Parrat formalism. This information is also discussed in the lecture video. Best wishes.
@@Bilim-Teknoloji-TarihIf we manually input thickness, roughnes and electron densities of each layer in the XRR simulation programs then we get the simulation XRR curve. Thank for your kind answer.
@@mingfengli8187 You are welcome. Some programs automatically calculate the parameters (thickness, roughness, density) after entering layers and their nominal values.
Thank you professor. very useful
You are welcome.
In xrr when we do footprint correction so what is the correct multiplication factor for intensity?
Hi Nisha Makani. It depends on your data. Some commercial simulation programs do it automatically.
Hello dr. How can I Communication with you .
I am want to ask you about Infrared (( Portion of Reflected and Transmitted Radiation: Fresnel Equations ))
You can write an e-mail to akdogan@gtu.edu.tr.
Where is the alignment animation from?
Hi. I've been using this animation in my lectures for the last ten years. But I don't remember where I got it from or who gave it to me. Maybe a friend or a student gave it to me. I would be very happy if you know the source and share it with me. Best wishes.
Sir, I have a very thin Pt layer (nominal thickness is 1nm) deposited by magnetron sputtering on Si wafer. the thickness of the native oxide layer of Si is similar to the deposited Pt layer. however, the native oxide layer thickness changes every time when try to fit the curve. could yu briefly explain the reason? Thanks you so much!
Hi MemetTursun.
First, you need to define the layers with the correct electron densities. That is, without changing the electron densities of the Si, SiO2 and Pt layers, the table values should be entered as they are. You can get them from webelements.com. And try to fit the XRR curve with nominal thicknesses.
If it does not work, you can manipulate the roughnesses.
If the simulation still does not fit the data, you can slightly increase the Pt density and play with roughnesses. But not too much.
Additionally, you should get the best fit around the critical angle (before and after). If this first part of the XRR curve is not well-fitted, the fit parameters (thickness, roughness, density) may be incorrect.
I wish you success.
@@Bilim-Teknoloji-Tarih dear Professor Akdogan, Thank you for your quick reply! I will try the way you mentioned. Also, I have other one question: when fit the curves for different Pt thickness, the resulted SiO2 layer thickness is different for different sample, in spite of very good fit for different sample. what do you think the reason might be?
Thank you very much !
Dear@@memettursunabduqadir4806. This should not be the case if you are using the same Si/SiO2 substrates. Something must be wrong.
emeğinize sağlık çok faydalı
Teşekkür ederim. Çok selamlar.