**Introduction**

**Chapter 1**

**Provisional chapter**

**Introductory Chapter: The Multiple Applications of**

**Introductory Chapter: The Multiple Applications of** 

The vibrational spectroscopies have been largely employed in the determination of the molecular structure and played a central role in many areas, from fundamental chemistry to materials engineering. Among these techniques, the Raman spectroscopy is essential today in the study of nanostructured materials and biological systems in *in situ* and *in vivo* conditions. In addition, by intensification process, very small quantities can be analyzed (for certain cases in the limit of single molecule regime). Detailed information about the molecular structure can be obtained, because each vibration of atoms shows a characteristic position and intensity. Both position and intensity are influenced by the chemical environment, or in other words by

The Raman spectra have a different origin compared to infrared absorption (IR); an inelastic scattering process is responsible for the appearance of the vibrational bands. In IR spectros-

photon energy must be coincident with the energy difference between two available states. Thus, *EN* − *E*<sup>1</sup> = *h*, being *h* the Planck's constant. In Raman spectroscopy, a molecule can scatter a monochromatic (*νo*) radiation. Typically, lasers with photon energies ranging from UV to near-IR region are used in the Raman experiments. The elastic scattering is called Rayleigh scattering, and it is much more intense than the inelastic Raman scattering (approximately 10−8 lower than the intensity of the incident radiation). The Raman spectrum appears in a

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

, *E*<sup>2</sup> , *E*<sup>3</sup>

,… *EN*), it means that

DOI: 10.5772/intechopen.75795

**Raman Spectroscopy**

**Raman Spectroscopy**

Gustavo M. Do Nascimento

**1. Introduction**

**2. Raman scattering**

http://dx.doi.org/10.5772/intechopen.75795

Additional information is available at the end of the chapter

chemical bonds, inter- and intramolecular forces.

copy, the radiation is absorbed by available vibrational states (*E*<sup>1</sup>

wavelength (*λo*) slightly higher or lower than the incident radiation [1–5].

Gustavo M. Do NascimentoAdditional information is available at the end of the chapter

#### **Introductory Chapter: The Multiple Applications of Raman Spectroscopy Introductory Chapter: The Multiple Applications of Raman Spectroscopy**

DOI: 10.5772/intechopen.75795

Gustavo M. Do Nascimento

Additional information is available at the end of the chapter Gustavo M. Do NascimentoAdditional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.75795
