Need Info: Bi2Te3 Crystal Structure, Grain Size & Lattice Parameter

[mahedi]

need urgent information

Dear All,

Can anyone inform me the following things on urgent basis ?

- The crystal structure of Bi2Te3 is Rhombohedral or Hexagonal ?
- How can I calculate the grain size from the XRD data/curve for Bi2Te3 ?
- how to calculate the lattice parameter of Bi2Te3 (Rhombohedral/Hexagonal crystal structure) from the XRD data/curve ?

Providing such information would be very much helpful to me.

Sincerely
Mahedi

 

[DaveC426913]

We don't spoonfeed. Show your work. We'll try to guide.

 

[mahedi]

Now I am working on 95% Bi2Te3- 5% Bi2Se3 thermoelectric material doped with SbI3 , fabricated by gas atomization in powder form. Next I want to consolidate the powder into the bulk and measure the thermoelectric properties.

In some literature I found that Bi2te3 crystal structure is rhombohedral and in some other as Hexagonal. So I am confused about it.

After getting the XRD spectram of the powder, I tried to measure the lattice parameter and grain size.

From the optical microscopy I got the view of the grain size which is few micrometer, but by calculating from the half width of XRD main peak the value shows in few nanometers, that put me farther confusion.

About the lattice parameter I don't know the exact equation and the process.

Now these created an obstacles in my research that stopped my advancement.

If you want to know any more things than kindly inform me.


Mahedi.