DAFS - Universidad de Zaragoza
DAFS - Universidad de Zaragoza DAFS - Universidad de Zaragoza
Abs II II EXAFS and EDAFS best fit results Abs. Sample→ paths (Å)↓ (As abs -As II ) // (As abs -As II ) ⊥ (As abs -P II ) // (As abs -P II ) ⊥ (As abs -In III ) // (As abs -In III ) ⊥ %P // % P ⊥ II InAs Bulk 4.284 4.284 - - 5.023 5.023 - - As,P In InAs/InP (pseud.) 4.15 4.29 - - 4.87 5.13 - - II shell distances CP1276 (EXAFS e ⊥ & e // ) 4.16±0.06 4.23±0.04 4.19±0.07 4.17±0.03 4.88±0.03 4.93±0.06 0.3±0.1 0.5±0.1 Strain P content CP1276 (DAFS e ⊥ ) - 4.30±0.04 - 4.20±0.06 - - - 0.4±0.2 Pure strained InAs or InAsP alloy ? I3701 (EXAFS e ⊥ & e // ) 4.15±0.06 4.25±0.04 4.15±0.07 4.18±0.03 4.87±0.03 4.94±0.06 0.4±0.1 0.6±0.1 I3701 (DAFS e ⊥ ) - 4.22±0.04 - 4.19±0.06 - - - 0.4±0.3 32/50
EXAFS (ε // & ε ⊥) Similar results for the 2 samples Mixing of two different As environments Strained InAs & InAsP alloy ? Intermixing As/P at the QWrs/capping interface P diffused QWrs Nice example of DAFS spatial selectivity and of strong EXAFS/DAFS complementarity GIDAFS probes the QWrs As atoms (the contribution of each atom depends on Q) EXAFS probes all As atoms EDAFS (ε ⊥) Different results for the 2 samples Different As-As and As-P II shell dist. CP1276: InAs QWrs + As/P intermixing at interface & capping I3701: InAsP QWrs + As/P intermixing at interface & capping 33/50
- Page 1 and 2: Universidad de Zaragoza Curso de Ma
- Page 3 and 4: TÉCNICAS EXPERIMENTALES µ I diff
- Page 5 and 6: EL DAFS El DAFS es la estructura fi
- Page 7 and 8: Resonant atomic scattering factor f
- Page 9 and 10: y 0 Structure factor: Multi-wavelen
- Page 11 and 12: I F diff 0 F 0 Análisis de datos D
- Page 13 and 14: Using the path formalism for descri
- Page 15 and 16: Spatial selectivity : GaAs xP 1-x/G
- Page 17 and 18: TEM InAs/InP QWrs AFM 200nm GaN/AlN
- Page 19 and 20: Local structure study of InAs/InP Q
- Page 21 and 22: As-O As K-edge EXAFS (BM8-ESRF) Int
- Page 23 and 24: Grazing incidence diffraction BM2-D
- Page 25 and 26: GI-DAFS (Grazing Incidence DAFS) k(
- Page 27 and 28: Diffraction Intensity (a.u.) GIDAFS
- Page 29 and 30: Abs II EXAFS and EDAFS best fit res
- Page 31: GIDAFS oscillations analysis CP1276
- Page 35 and 36: Applications : Nanostructures III-V
- Page 37 and 38: Applications : Nanostructures III-V
- Page 39 and 40: BQ GaN/AlN 10ML : EXAFS vs DAFS k
- Page 41 and 42: BQ GaN/AlN : EDAFS simulations h=2.
- Page 43 and 44: Orden de carga y reflexiones prohib
- Page 45 and 46: Estado electrónico de los sitios o
- Page 47 and 48: Anisotropía del factor de dispersi
- Page 49 and 50: Zona del umbral (DANES) Modelo refl
- Page 51 and 52: Prepico Cálculos “ab initio” d
- Page 53: Grazing Incidence Diffraction Anoma
EXAFS (ε // & ε ⊥)<br />
Similar results for the 2 samples<br />
Mixing of two different As<br />
environments<br />
Strained InAs & InAsP alloy<br />
?<br />
Intermixing As/P<br />
at the QWrs/capping<br />
interface<br />
P diffused QWrs<br />
Nice example of <strong>DAFS</strong> spatial<br />
selectivity and of strong<br />
EXAFS/<strong>DAFS</strong> complementarity<br />
GI<strong>DAFS</strong> probes the QWrs As atoms (the<br />
contribution of each atom <strong>de</strong>pends on Q)<br />
EXAFS probes all As atoms<br />
E<strong>DAFS</strong> (ε ⊥)<br />
Different results for the 2 samples<br />
Different As-As and As-P II shell dist.<br />
CP1276: InAs QWrs + As/P<br />
intermixing at interface<br />
& capping<br />
I3701: InAsP QWrs + As/P<br />
intermixing at interface<br />
& capping<br />
33/50
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