Graduate Help with determination of crystal orientation

[HAYAO]

Dear all,

Hi, I am looking for a non-destructive method of determining the crystal orientation of a smaller-than-50x50x50 μm single crystal, mounted on a quartz substrate.

I've considered several x-ray methods like Laue method, or microfocused XRD, but there are some experimental difficulty when using x-ray methods because the crystal is placed on a quartz substrate. Quartz substrate is amorphous (made with fused quartz glass) and it most likely adds very broad peak background to the measurement, which would be terrible in cases where strong diffraction peaks are hard to obtain for crystals such as very small ones I mentioned above.

Optical methods (optical crystallography) might work when polarized microscopes are used. However, some samples I am looking at are triclinic, meaning none of the crystallographic axis could match the optical axis.

EBSD will obviously not work because I need to put them in SEM with electron beam that can kill the material.

Can anyone suggest me a good method?EDIT: Crystallographic information file is already available obtained previously by single crystal x-ray.Thank you.(Note to the moderators: I was not sure if I should put this in this general physics forum or atomic and condensed matter forum. If this place is inappropriate, please move the thread. Thank you.)

 

[Vagn]

Dear all,

Hi, I am looking for a non-destructive method of determining the crystal orientation of a smaller-than-50x50x50 μm single crystal, mounted on a quartz substrate.

I've considered several x-ray methods like Laue method, or microfocused XRD, but there are some experimental difficulty when using x-ray methods because the crystal is placed on a quartz substrate. Quartz substrate is amorphous (made with fused quartz glass) and it most likely adds very broad peak background to the measurement, which would be terrible in cases where strong diffraction peaks are hard to obtain for crystals such as very small ones I mentioned above.

Optical methods (optical crystallography) might work when polarized microscopes are used. However, some samples I am looking at are triclinic, meaning none of the crystallographic axis could match the optical axis.

EBSD will obviously not work because I need to put them in SEM with electron beam that can kill the material.

Can anyone suggest me a good method?EDIT: Crystallographic information file is already available obtained previously by single crystal x-ray.Thank you.(Note to the moderators: I was not sure if I should put this in this general physics forum or atomic and condensed matter forum. If this place is inappropriate, please move the thread. Thank you.)

Could you try grazing incidence x-ray diffraction, as this should minimise you obtain from the substrate?

 

[DrDu]

However, some samples I am looking at are triclinic, meaning none of the crystallographic axis could match the optical axis.

Isn't this so because in a triclinic crystal the choice of crystallographic axes is arbitrary?

 

[HAYAO]

Could you try grazing incidence x-ray diffraction, as this should minimise you obtain from the substrate?

Cool. This sounds promising, although none of the equipment in my university has this. Hopefully some university in Tokyo does...

Isn't this so because in a triclinic crystal the choice of crystallographic axes is arbitrary?

Yes indeed.

 

[ZapperZ]

We have used RHEED before on ultra-thin films and were able to either remove, or identify signals from the substrate. This is another grazing-angle technique that has been suggested. However, it uses electron beam, and depending on the equipment, you may not be able to focus the beam into that small of an area.

Zz.

 

[HAYAO]

We have used RHEED before on ultra-thin films and were able to either remove, or identify signals from the substrate. This is another grazing-angle technique that has been suggested. However, it uses electron beam, and depending on the equipment, you may not be able to focus the beam into that small of an area.

Zz.

Thank you Zz,

You are absolutely right. If the method wasn't destructive for the particular material I am using, I would have definitely used RHEED or any sort of electron diffraction methods. Unfortunately, my material may be too big for TEM, non-conductive for SEM (requires Pt coating), and too weak against electron beam.EDIT: Thank you moderator for moving this thread to a more suitable forum.