EELS of Platinum (Pt)
- Practical Electron Microscopy and Database -
- An Online Book -
Electron microscopy
  Microanalysis | EM Book                                                                   http://www.globalsino.com/EM/  
 

 

Table 2319 lists the common applications of Pt EELS edges. Figure 2319a shows that the background increases dramatically with increase of the thickness of TEM specimen, while the signal of Pt M4,5 edge decreases significantly. The highest signal in the range of these TEM specimen thicknesses for Pt occurs at 20 nm.

Table 2319. Common applications of Pt EELS edges.

Edge Energy (eV) Application
M4,5 2200 Elemental quantification

EELS of Pt M4,5 edg

Figure 2319a. EELS of Pt M4,5 edge.

The sandwich structure shown in Figure 2319b (a) is composed of three layers: SrTiO3, PbTiO3, and Pt. An amorphous Ti-rich interfacial layer as well as nanometer size precipitates was formed at PbTiO3/Pt interfaces. In the low-loss region in EELS from the different layers shown in Figure 2319b (b), the energy peaks labeled A–H for SrTiO3 and a–h for PbTiO3 are formed by interband transitions which are typical in bulk SrTiO3 and PbTiO3 [1]. The strong peaks H/h and H’/h’ arise from transitions of Ti 3p to higher energy levels such as Ti 3d, Ti 4s, forming Ti M2,3 edge. In the precipitates, the transitions h and h are reduced in intensity because these precipitates might be Ti-deficient. In Figure 2319b (c), the two core loss EELS profiles from SrTiO3 and PbTiO3 layers show clear splitting of the Ti-L2,3 edges, while for the interfacial layer the splitting at the Ti-L3 edge is much less and the splitting at the Ti-L2 edge disappears. The splitting of Ti-L2,3 edges reflects the hybridization and ligand field strength of Ti–O atomic interaction so that the reduction of splitting in the interfacial layer reflects the weaker Ti–O bonding force. Due to the similar hybridization of O 2p states with Ti 3d in the conduction band, the energy region from 530 eV to 536 eV is split into two subbands t2g (marked peak 1) and eg (marked peak 2). Figure 2319b (d) shows the EEL spectra of Pb- and Pt-M4,5 edges.

SrTiO3, PbTiO3, and Pt

Figure 2319b. (a) TEM image of sandwich structure ( SrTiO3, PbTiO3, and Pt), and (b) low-loss region in EELS, (c) Ti-L2,3 and O-K edges, and (d) Pb- and Pt-M4,5 edges from the different layers. The black arrows in (d) denote the positions of Pt-M4,5 edges. Adapted from [2]

 

 

 

 

 

 

 

 

[1] K. V. Benthem, C. Elsasser, and R. H. French, J. Appl. Phys. 90, 6156 (2001).
[2] L. F. Fu, S. J. Welz, and N. D. Browning, M. Kurasawa, and P. C. McIntyre, Z-contrast and electron energy loss spectroscopy study of passive layer formation at ferroelectric PbTiO3/Pt interfaces, Applied Physics Letters, 87, 262904 (2005).

 

;