what we have now:

Post on 05-Feb-2016

24 Views

Category:

Documents

0 Downloads

Preview:

Click to see full reader

DESCRIPTION

What we have now:. Data:. Theory: Born Approximation model , Parratt’s theory , Sinha’s DWBA (including calculation for Yoneda wings). The rule we and our codes followed:. Experimental measured intensity:. Depends on surface tension γ !. Resolution function is very important!. - PowerPoint PPT Presentation

TRANSCRIPT

What we have now:

XR GID Kscanwater

Au monolay

erAu

multilayer

Data:

Theory:Born Approximation model , Parratt’s theory , Sinha’s DWBA (including calculation for Yoneda wings)

The rule we and our codes followed:

2

2max

1( ) ( )F z z x y

re xs y

I R q q dq dqq q

Experimental measured intensity:

Constant for K-scan!(constant qz)

Depends on surface tensionγ!

Resolution function is very important!

Au monolayer reflectivity fitting

With our fitting code,we’re ableto fit the reflectivity very well evenfor Au multilayer,but always get negative density part due to the broadening of error functions.

Fitting resolution function(fixed γ=72 mN/m):Blue – fixed Vert. Slit(0.52mm),Hori. Slit(1.89mm) (sli=[11,3])Red – fitted Vert. Slit(0.53mm),Hori. Slit(3.59mm)

Water kscan '63-69‘ Qz=0.22

Even water can not be reproduced well.(due to temperature change or pollution?)

Resolution function calculated from slits size needs to be corrected?

Fitting resolution function:Blue – fixed Vert. Slit(0.52mm),Hori. Slit(1.89mm)Red – fitted Vert. Slit(0.52mm),Hori. Slit(3.61mm)

Water '71-77', sli=[11,3],bac=0.5 ,Qz=0.33

Unknown peak presents at Q~0.073,The position doesn’tchange with γ.

Water '79-106', sli=[11,3],bac=0.5 ,Qz=0.44

The slit size Vert.=0.52 Hori.=1.89 could fit the data perfectly.No cerrection to resolution function.And slit(0.52,3.60) seems also work not bad.

Need to figure out!

Do we need to correct our resolution function from slit (0.52,1.89) to slit (0.52,3.6)?

Reason?

Big problem: Ununiformity of sample (beam damage?)

& Lack of reproducibility

Three data sets for Qz=0.22 are different from each other –monolayer is not reproducible…

black—148(w/thoils ), red—217 blue– 273

Surface tension rules!monoAu ‘217-', sli=[11,3],bac=0.5 ,Qz=0.22

Highly depends on surface tension blue-- γ =18 (~heptane) m

agenta–-γ =30 red–- γ =72(water)

Surface tension fitting(with fixed slit0.52,1,89)

fitted γ =45 mN/m (between water 72 & Heptane ~20)

monoAu ‘217-', sli=[11,3],bac=0.5 ,Qz=0.22

monoAu ‘313-', sli=[11,3],bac=0.5 ,Qz=0.33

fitted γ =45 mN/m

monoAu ‘299-', sli=[11,3],bac=0.5 ,Qz=0.44

fitted γ =48 mN/m

Due to the surface tension difference between water and solvent for nanoparticle?

Contains informationabout the propertyand structure of the Au nanoparticle films?Are we able to fit this part by modifying our codes?

Should we compare it to thin solvent material film on water surface?

Can we make samplesmore uniform and reproducible?

After compression(compared to uncompressed results)

Au 331,Qz=0.22 ,red-- fitted γ =31 mN/mblue-- uncompressed γ =45 mN/m

Au 345 Qz=0.44 , red--fitted γ =38 mN/m blue—uncompressed γ =48 mN/m

How does the compression lower surface tention of this system?Through increasing thickness of the solvent or increasing density of nanoparticles?

Surface tension of Heptaneγ(mN/m-1 ±0.02 mN/m-1)

Qz=0.22, k-scan217

Qz=0.33,k-scan313

Qz-0.44,k-scan229

Beam vert. size D=0.04

Beam vert. size D=0.04mm, slit=[11,3]kscan217,Qz=0.22

D=0.12mm, slit=[11,3], Kscan313,Qz=0.33

D=0.12mm, slit=[11,3] ,Kscan299,Qz=0.44

Water sample 3 :k scan 133-139,Qz=0.22s1=[1,0.04]mm,slit=[11,3]pixels, γ=72,65,60mN/m

Water sample 2: k scan 71-77,Qz=0.33s1=[1,0.06]mm, slit=[11,3]pixels, γ=72,65,60mN/m

Water sample2 :k scan 79-106,Qz=0.44s1=[1,0.06]mm, slit=[11,3]pixels, γ=72mN/m

Water sample 3 : k scan 133-139,Qz=0.22s1=[1,0.04]mm,slit=[22,3]pixels, γ=72,65,60mN/m

Water sample 2 : k scan 71-77,Qz=0.33s1=[1,0.06]mm,slit=[22,3]pixels, γ=72,65,60mN/m

Water sample 2 : k scan 79-106,Qz=0.44s1=[1,0.06]mm,slit=[22,3]pixels, γ=72,65,60mN/m

Au sample 2 : k scan 217-241,Qz=0.22s1=[1,0.04]mm,slit=[11,3]pixels, γ=45mN/m

Change in horizontal electronic slitWater sample 3 :k scan 133-139,Qz=0.22

Change in vertical electronic slitWater sample 3 :k scan 133-139,Qz=0.22

Water sample 3 : k scan 133-139,Qz=0.22s1=[1,0.04]mm,slit=[22,3]pixels, γ=72mN/m

Water sample 2 : k scan 71-77,Qz=0.33s1=[1,0.06]mm,slit=[22,3]pixels, γ=72N/m

Water sample 2 : k scan 79-106,Qz=0.44s1=[1,0.1]mm,slit=[22,3]pixels, γ=72mN/m

Au sample 2 : k scan 217-241,Qz=0.22s1=[1,0.04]mm,slit=[11,3]pixels, γ=45mN/m

Oct2008 sample 2,Au monolayer Kscan Qz=0.22(#217),0.33(#313),0.44(#299)sli=[11,3]pix,s1=[1,0.04/0.12]mm, γ=45mN/m

Aug2008 sample 1, Au monolayer reflectivity fitting right figure shows the corresponding electron density profile

(smoothing parameter σ=6)

Aug2008 sample 1, Au monolayer beta-scan(#91-95)changing smoothing parameter σ=6(top)3(bottom)

right panel shows the corresponding electron density profile

Aug2008 sample 1, Au monolayer beta-scan(#91-95)α=1.866,smoothing parameter σ=3

right panel shows the difference between data and fitting (data/fitting)

Beta-scan peak vicinity surface tension fitting

Aug2008 sample 1, Au monolayer beta-scan(#97-101) α =2.488,smoothing parameter σ=3

right panel shows the difference between data and fitting (data/fitting)

Aug2008 sample 1, Au monolayer beta-scan(#102-111) α =3.111,smoothing parameter σ=3

right panel shows the difference between data and fitting (data/fitting)

Aug2008 sample 1, Au monolayer beta-scan(#91-95)changing smoothing parameter σ=3 2.8

The decay curves show the beta-scan fitting without structure factor

Aug2008 sample 3, Au multilayer beta-scan(#251-254)α=1.696,γ=72(cyan),60(red) mN/m

peak in a bumpcan’t fit…

Aug2008 sample 3, Au multilayer beta-scan(#255-260)α=2.262,γ=45(blue),60(red) mN/m

When the specular peak is merged in a bump of structurefactor, it’s difficult to fit the vicinity of the peak.

Aug2008 sample 3, Au multilayer beta-scan(#261-270)α=2.8282,γ=40(magenta),45(blue),60(red) mN/m

Aug2008 sample 3, Au multilayer beta-scan(#286-305)α=3.394,γ=45(blue),60(red) mN/m

Aug2008 sample 1, Au monolayer beta-scan(#91-95)α=1.866,smoothing parameter σ=3

Oct2008 purple---sample2(mono) scan#217, blue ---sample4(multi) scan#469

red ---sample5(multi) scan#525

top related