it is quite possible for there to be significant disorder in the first shell. Vacancies can cause this or a size mismatch with a dopant atom. In addition, oxygen is much less massive than iron and so can have much higher thermal vibrations. Cheers, Carlo On Fri, 2 Oct 2009, Hashem Stietiya wrote:

Dear All,

Does the Debye Waller value for the first shell have to be smaller than that of the second shell? can you have a situation where the Debye Waller value for the Zn-O first shell is 0.011 and for the Zn-Fe second shell is 0.003? so if there is thermal or static disorder in the first coordination shell,that must be the case for the second coordination shell?

Best Regards,

Hashem Stietiya Louisiana State University

-- Carlo U. Segre -- Professor of Physics Associate Dean for Graduate Admissions, Graduate College Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre@iit.edu http://www.iit.edu/~segre segre@debian.org