Nanoceramics: Synthesis, Characterizations and Applications
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3.9 Infrared Spectroscopy (IR)
Infrared Spectroscopy is also known as vibrational spectroscopy. It is a powerful,
sensitive and non-destructive tool for analyzing, characterizing and identifying both
organic and inorganic molecules. It also helps in identifying functional groups present
over a depth of about 1 μm [64]. When a sample is irradiated with light, the bonds
present in the sample molecule absorbs light in the infrared region and start to vibrate.
The absorbed light is characteristic of the bonds present in the molecule. IR spectrum
is obtained by plotting the amount of light absorbed against wavelength in the region
of 4000–400 cm
−1 . This spectrum is known as ‘molecular fingerprint’ that helps to
identify samples.
Fourier Transform—Infrared Spectroscopy (FT-IR) produces a spectrum with
high spatial resolution, good signal-to-noise ratios and it also enables measuring a
broad region of the spectrum in short duration [65]. Fourier Transform is a mathematical process carried out to convert the raw data into actual spectrum. Solid,
liquid, or gaseous samples can be studied with FT-IR. Attenuated Total Reflection—
Infrared Spectroscopy (ATR-IR) is used to study solid or liquid samples without
further preparation. It uses the property of internal reflection to analyze the sample.
The infrared radiation penetrates the samples to a depth between 0.5–2 mm. Rapid
sampling and ease of handling are main advantages of this method.
3.10 X-Ray Photoelectron Spectroscopy (XPS)
X-ray Photoelectron Spectroscopy is also known as electron spectroscopy for chemical analysis (ESCA). It is a surface-sensitive spectroscopic technique that does a
quantitative elemental analysis of the surface of the sample. The elemental composition, empirical formula, chemical and electronic state of the elements present in the
material can be measured by this method [66]. The sample surface is irradiated with a
beam of X-rays and the kinetic energy of the emitted electrons from the top 1–10 nm
of the material surface is measured [67]. The photoelectron spectrum is recorded by
plotting the number of ejected electrons with respect to a range of electron kinetic
energies. Atoms emitting particular energy is recorded as peaks. Identification and
quantification of the different elements present on the material surface can be done by
studying the energies and intensities of the peaks. XPS is a useful technique as it not
only enables identification of elements present on the surface but also the elements
it is bonded to and its oxidation state.
143
3.9 Infrared Spectroscopy (IR)
Infrared Spectroscopy is also known as vibrational spectroscopy. It is a powerful,
sensitive and non-destructive tool for analyzing, characterizing and identifying both
organic and inorganic molecules. It also helps in identifying functional groups present
over a depth of about 1 μm [64]. When a sample is irradiated with light, the bonds
present in the sample molecule absorbs light in the infrared region and start to vibrate.
The absorbed light is characteristic of the bonds present in the molecule. IR spectrum
is obtained by plotting the amount of light absorbed against wavelength in the region
of 4000–400 cm
−1 . This spectrum is known as ‘molecular fingerprint’ that helps to
identify samples.
Fourier Transform—Infrared Spectroscopy (FT-IR) produces a spectrum with
high spatial resolution, good signal-to-noise ratios and it also enables measuring a
broad region of the spectrum in short duration [65]. Fourier Transform is a mathematical process carried out to convert the raw data into actual spectrum. Solid,
liquid, or gaseous samples can be studied with FT-IR. Attenuated Total Reflection—
Infrared Spectroscopy (ATR-IR) is used to study solid or liquid samples without
further preparation. It uses the property of internal reflection to analyze the sample.
The infrared radiation penetrates the samples to a depth between 0.5–2 mm. Rapid
sampling and ease of handling are main advantages of this method.
3.10 X-Ray Photoelectron Spectroscopy (XPS)
X-ray Photoelectron Spectroscopy is also known as electron spectroscopy for chemical analysis (ESCA). It is a surface-sensitive spectroscopic technique that does a
quantitative elemental analysis of the surface of the sample. The elemental composition, empirical formula, chemical and electronic state of the elements present in the
material can be measured by this method [66]. The sample surface is irradiated with a
beam of X-rays and the kinetic energy of the emitted electrons from the top 1–10 nm
of the material surface is measured [67]. The photoelectron spectrum is recorded by
plotting the number of ejected electrons with respect to a range of electron kinetic
energies. Atoms emitting particular energy is recorded as peaks. Identification and
quantification of the different elements present on the material surface can be done by
studying the energies and intensities of the peaks. XPS is a useful technique as it not
only enables identification of elements present on the surface but also the elements
it is bonded to and its oxidation state.