need urgent help

mahedi

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