Xeds, Eels- Class Report

Rajasekarakumar Vadapoo Department D of Physics, University of Puerto Rico,PR-00931,USA. More info: http://nanophysics.wordpress.com ttp://nanophysics.wordpress.com

X-ray ray Energy Dispersive Spectrometry (XEDS) and Electron Energy Loss Spectrometry (EELS) (EELS)- Report # 2. Aim: To confirm the atomic composition of the given sample by the spectroscopic method Xray Energy Dispersive Spectrometry trometry (XEDS) and reconfirming by using Electron Energy Loss Spectroscopy (EELS). Experiment details: The experiments were carried out in Carl zeiss 200 KeV TEM with the capability of spectroscopic measurements of X XEDS and EELS. The sample used was Fe3CoO4 nanoparticles. Results and Discussions:
Image: The fig.1 shows that the TEM image of Fe3CoO4 nanoparticles. As we see we have a distribution of sizes of the nanoparticles ranging from 7.98 nm to as big as 22.7 nm. If we closely look at the shapes of the nanoparticles, it shows the crystal facets. Fig.2. shows the TEM image of the region where we have carried out the XEDS and EELS measurements of the given nanoparticles. The black region in the left corners of the image is due to the selective area aperture corners.

Fig. 1 TEM image of Fe3CoO4 nanoparticles

Fig.2. The area of XEDS &EELS taken.


X-ray Energy Dispersive Spectrometry (XEDS):

Fig. 3. The XEDS plot shows the presence of the elements present in the sample for the corresponding peak. 1600 8.05

1400 1200 1000 800 600 400

0.51

4.51 6.41

0.74

200

0.93

8.92 6.93

4.97

0 0

1

2

3

4

5

6

7

8

9

Energy in keV

Fig. 4. The plot shows the measured XEDS energy of the peaks in keV.

10

Experimental (keV) 0.51 0.74 0.93 4.51 4.97 6.41 6.93 8.05 8.92

Reported (keV) 0.525 0.776 0.93 4.508 4.931 6.398 6.924 8.04 8.904

Corresponding lines O Kα Co Lα Cu Lα Ti Kα Ti Kβ Fe Kα Co Kα Cu Kα Cu Kβ

Table. 1. Shows the experimentally observed XEDS peaks and the corresponding reported value of X-Ray emission and absorption edge energies. Fig. 3 & 4 shows the measured XEDS peaks corresponding possible elements and the corresponding energies respectively. Table 1. Clearly shows that the experimentally observed XEDS peaks exactly match with the corresponding reported lines of the element as shown in the table as well as the corresponding elemental details shown in fig.3. From these details we can confirm that the nanoparticles what we measured were containing the atomic elements Fe, Co & O.
Energy Loss Spectrometry (EELS): The measured EELS spectrum of the given sample is given below for the corresponding elements present

Edge-type

Reported edges (eV) Measured edges (eV) Kα K(a,b) 1st Edge 2nd Edge C-K 277 282 ~ 277 ~ 292 O-k 525 531 ~532 ~ 538 Table. 2. Experimentally measured X-Ray energy emission and absorption edges reported edges of the element C & O. Reported edges (eV) Measured edges (eV) Lα Lβ1 Lν1 LIII(ab) LII(ab) 1st Edge Co-L3 776 791 794 779 794 ~ 785 Fe-L3 705 718 721 709 720 ~ 715 Table.3. Experimentally measured X-Ray energy emission and absorption edges reported edges of the element Co & Fe.

3rd Edge ~ 318 ~ 565 along with the

Edge-type

2nd Edge ~ 805 ~ 725 along with the

Digits

Parallel EELS O - K

Intensity

100.0

50.0

0.0

530.0

Digits

550.0

Digits

Parallel EELS Co - L3

570.0 Energy Loss

590.0 eV

Parallel EELS Fe - L3

40.0

40.0

Intensity

Intensity

30.0

20.0

20.0 10.0

0.0 0.0

-10.0 740.0

760.0

780.0 Energy Loss

800.0

680.0 eV

700.0

720 720.0 Energy Loss

740.0 eV

Fig. 5. EELS spectrometry spectrums obtained in the experiment for the constituent elements of the sample along with carbon. The fig.5 & table.2, 3 show that the measured edges have little shift for most of the constituent tituent elements. It could be overcome by having the correction of exact Zero loss peak at zero eV. Overall the measured edges match with the reported edges of the given constituent elements which show that the particular elements are present in the given sample. The broadening of peaks which cover the area of edges shows that it could have several edges e merges together and or contains some other fine structure details along with the edges. edges

Conclusions: We have carried out the Transmission Electron Microscopy imaging maging of given Fe3CoO4 nanoparticles. The he elemental characterization using XEDS & EELS show the existance of the atomic elements Fe, Co and O in the measured region of the sample.