Dear Researchers,
I have to do the P-E and Dielectric measurements of the BiFeO3 thin films. In order to study the mentioned properties which substrate will be the best suitable among Si and ITO. What should be the composition and order of the conductivity of the substrate.
Thank you in advance.
Dear Nadeem,
The ferroelectric properties of the thin films have been reported to be strongly dependent on the crystallinity and orientation. So, you can try STO, Si, Al2O3 or some other subtrates. I have written one paper on Thin films, maybe you can get some information about your question.
Wish you good luck.
Dear Venkata Ramana Mudinepalli Sir,
Thank you for your valuable suggestion.
Actually, I mean to say that how much should be the conductivity of the substrate on which we are depositing film.
Substrate need not be conducting, they can be insulating also (like SiO2/Si, glass, quartz, alumina etc.).
Firstly it depends at what temperature you are growing/annealing your BFO thin films. The substrates must withstand that temperature.
Secondly, on insulating substrates you need a stable electrode, preferable a high temperature resistant electrode, such as a thin platinum layer which sticks well to the insulating substrate.
Now conducting substrates (like metal foils) would not help, because when you grown BFO films at a high temperature you will inter diffuse with the metallic substrate. Moreover you cannot select a silicon substrate also, because BFO will inter diffuse into silicon. You will not be able to get silicon substrates with metallic conductivity.
For electrode purposes you need metallic conductivity to measure the PE loops properly, and this is possible only with the use of platinum foil substrates, or putting adherent platinum thin films onto other substrates.
ITO coated glass will not allow you to go more than 400 to 450 deg C, because glass will begin to soften around 450 to 500. and Silicon substrate with metallic conductivity will not be available.
both sides of the sample should be conductive, because you have to make a capacitor. Regards
Dear K. Sreenivas Sir,
Thank you very much for your valuable response and information.
Your answer contains many points about which I was little confused.
I agree with Mohammad E. Ghazi.
You have to select conducting substrate such as SNTO (Nb-doped STO), ITO, etc. In addition, SNTO with higher Nb-doping percentage will be more conducting and suitable as a bottom electrode. There are other substrate too but to avoid highly expensive substrates you can make conducting layer on Si substrate and deposit BFO film on it.
After deposition of BFO, make Gold/Silver contact on the film as well as on the substrate for PE measurement.
I hope attached article will help you.
Article Effect of strain on the modifications in electronic structur...
Pt/TiO2/SiO2/Si substrate is best for electrical and ferroelectric (P-E) measurements. You can use Pt as a bottom electrode. Mohd. Nadeem
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