Raman intensity : an important tool in the study of nanomaterials and nanostructures

Aneta Slodczyk ,  Philippe Colomban 

LADIR-CNRS (LADIR), 2 rue Henry Dunant, Thiais 94320, France

Abstract

The measurements of the relative Raman intensity are used mainly to map quantitatively the amount, distribution and degree of crystallisation of different phases in a material [1,2]. Our studies reveal that the analysis of the relative or absolute Raman intensity is much more powerful tool which allows to understand and characterize the modifications of the crystal/amorphous structure due to:

  •  changes of the long range order correlations as the function of the nanoregion organization in the case of PMN-PT [3] relaxor ferroelectric materials. The significant decrease of Raman intensity with the temperature increasing reveals the continuous evolution of the local symmetry towards the long range cubic one.
  • changes of the Si-O network caused by the depolymerisation resulting from the substitution of the Si4+ ions (covalent bonds) by the M+ cations (ionic bonds) [4,5] or by the incorporation of the metallic nanoprecipitates [5,6]. SiO4 tetrahedron is a strong chemical and vibrational entity and the Raman signature reveals the different conformations. The transition from a highly connected tetrahedral structure to a weakly connected tetrahedral units as caused by the addition of fluxing agents is reflected in the Raman spectrum by modifications of the Si-O intensity. If the laser excitation interact with the Plasmon absorption of Ag° or Cu° nanoparticles dispersed in the glass (ancient or modern) the Raman scattering probes only the Si-O bonds interacting with the M° nanoparticles and strong intensity changes are measured [6].

1. Ph. COLOMBAN, Spectroscopy Europe 15 [6] (2003) 8-15

2. G. GOUADEC, Ph. COLOMBAN, Progr. Cryst. Growth & Charact. Mat. 53  (2007) 1-56

3. A. SLODCZYK, Ph. COLOMBAN, M. PHAM-THI, J. Phys. Chem. Solids

4. Ph. COLOMBAN, J. Non-Crystalline Solids 323 (2003) 180-187

5.Ph. COLOMBAN, A. TOURNIE, L. BELLOT-GURLET, J. Raman Spectrosc.  37 (2006)  841-852

6. Ph. COLOMBAN, H. SCHREIBER, J. Raman Spectrosc. 36 (2005) 884-890

 

Related papers
  1. Proton diffusion in perovskites by Elastic and Quasi-Elastic Neutron Scattering measurement
  2. High pressure phase transitions in proton-conductor SrZrO3–based perovskites
  3. Raman evaluation of the proton diffusion coefficient in the pressure protonated perovskite electrolytes

Presentation: Oral at E-MRS Fall Meeting 2008, Symposium A, by Aneta Slodczyk
See On-line Journal of E-MRS Fall Meeting 2008

Submitted: 2008-05-22 11:21
Revised:   2008-06-13 16:32