DAFS - Universidad de Zaragoza
DAFS - Universidad de Zaragoza
DAFS - Universidad de Zaragoza
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
BQ GaN/AlN 10ML : EXAFS vs <strong>DAFS</strong><br />
k χ ϕ ϕ<br />
χ ϕ ϕ<br />
χ = ′<br />
− ) ′′<br />
( ) cos( −<br />
Q 0 A)<br />
EXAFS + sin( 0<br />
r E<strong>DAFS</strong> from EXAFS<br />
kχ(k)<br />
sample<br />
a (Å)<br />
C (Å)<br />
x_Al<br />
c/a<br />
Bulk<br />
3,188<br />
5,186<br />
-<br />
1,626<br />
GaN<br />
biaxial<br />
3,11<br />
5,26<br />
-<br />
1,69<br />
k (nm -1 )<br />
exp. E<strong>DAFS</strong><br />
<strong>DAFS</strong><br />
3,14 (diff.)<br />
5,23±0,03<br />
0,0±0,1<br />
1,67<br />
EXAFS<br />
3,15<br />
5,19±0,03<br />
0,22±0,07<br />
1,64<br />
A<br />
EXAFS<br />
X ray absorption (EXAFS)<br />
-GaK-edge<br />
- E ⊥ and // to growth plane<br />
-BM30, ESRF<br />
EXAFS : probe all Ga atoms (WL,<br />
interfaces, ... )<br />
E<strong>DAFS</strong> : max of F Ga : probe<br />
mainly the QD’s core (iso-strain<br />
volume)<br />
39/50
Change language