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M45_Raman spectroscopy.html
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<html>
<head>
<p class="head">Raman spectroscopy</p>
<link rel="stylesheet" type="text/css" href="exampleStyle.css"/>
<hr>
</head>
<body>
<p><font color=gray>[Under construction]</font> </p>
<div id="Overview">
<p class="thema">Overview</p>
<p><a class="def">Raman spectroscopy</a> involves analyzing the scattered <a class="black" href="https://cvertan.github.io/physics4dh.github.io/1_Light.html" target="frameterms">light</a> from a sample when illuminated by a single-color light beam. The resulting spectrum, which shows the intensity of light as a function of the <a class="black" href="https://cvertan.github.io/physics4dh.github.io/M45_Raman%20spectroscopy.html#Principle" target="_blank">Raman frequency shift</a> (the difference between the <a class="black" href="https://cvertan.github.io/physics4dh.github.io/13_EM_spectrum.html" target="frameterms">frequencies</a> of the incident and scattered light), provides direct information about the <a class="black" href="https://cvertan.github.io/physics4dh.github.io/32_Molecule.html" target="frameterms">molecular</a> vibrational frequencies of the sample. This information can be used to identify the molecular composition and even the different states of aggregation of the <a class="black" href="https://cvertan.github.io/physics4dh.github.io/32_Molecule.html" target="frameterms">molecules</a> by comparing them to known standard samples. By using different frequencies within the <a class="black" href="https://cvertan.github.io/physics4dh.github.io/18_visible_light.html" target="frameterms">visible</a> or <a class="black" href="https://cvertan.github.io/physics4dh.github.io/10_infrared%20light.html" target="frameterms">near-infrared</a> range to excite the Raman spectra, it is possible to obtain valuable insights for pigment identification since pigments can exhibit different scattering properties at different excitation frequencies. </p>
<p> </p>
</div>
<div id="Tasks">
<p class="thema">Research tasks & applications</p>
<p>Raman spectroscopy is well established non-destructive technique in the field of <b>cultural heritages</b>, as shown by a lot of scientific articles on valuable artistic objects in the last few years [<a class="ref" href=bibliography.html# > </a>]. Raman spectroscopy yields valuable information on the <b>molecular structure of the compounds characterizing each single colour in the drawing</b>. </p>
<p>For elemental as well as compound specific material analyses, Raman spectroscopy also might be combined with other non-invasive investigation methods like <a class="black" href="https://cvertan.github.io/physics4dh.github.io/M42_2_PIXE.html" target="_blank">PIXE</a>, <a class="black" href="https://cvertan.github.io/physics4dh.github.io/M42_1_XRF.html" target="_blank">XRF</a>, <a class="black" href="https://cvertan.github.io/physics4dh.github.io/M44_FTIR.html" target="_blank">FTIR</a>, which can be considered complementary. For ex., PIXE yields information on the elemental composition of colours, inks, and parchment, in particular unveiling possible variations over the entire surface of the drawing, while micro-Raman spectroscopy yields valuable information on the molecular structure of the compounds characterizing each single colour in the drawing. </p>
</div>
<div id="P">
<p class="thema">Principle</p>
<p> </p>
<p> </p>
<iframe width="600" height="400"
src="https://www.youtube.com/embed/57hRNhefXPg?autoplay=1&mute=1">
</iframe>
</div>
<div id="Equip">
<p class="thema">Equipment</p>
<p>Ocean Insight, Horiba, IS-Instruments, Enwave Optronics etc. are some of the manufacturer of instruments for Raman spectroscopy. Usually, the proper software needed for Raman analysis is provided by the manufacturer. </p>
<p> </p>
<table>
<tr>
<th>Instrument</th>
<!-- <th>Operating Range</th> -->
<th>Specification</th>
</tr>
<tr>
<td>LabRAM Odyssey </td>
<td><a target="_blank" href="https://www.horiba.com/int/scientific/products/detail/action/show/Product/labram-odyssey-1882/">www.horiba.com</a> </td>
</tr>
<tr>
<td>Ocean HDX 785 Preconfigured Raman Spectrometers </td>
<td><a target="_blank" href="https://www.oceaninsight.com/products/spectrometers/raman/?utm_campaign=N.+NIR-Spectroscopy&utm_term=raman%20spectrometer&utm_medium=ppc&utm_source=adwords&hsa_kw=raman%20spectrometer&hsa_mt=e&hsa_grp=133699447093&hsa_tgt=kwd-21733386&hsa_net=adwords&hsa_cam=11225377191&hsa_ver=3&hsa_acc=5588456569&hsa_src=g&hsa_ad=585306729042&gclid=CjwKCAjw1MajBhAcEiwAagW9MXCdxt1XsYR0PedM5CXq8VBpd6N-WkgZ6t85hM0MVBNFMhoaREAI8RoC4l8QAvD_BwE
3. ODIN compact deep UV Raman spectrometer https://is-instruments.com/odin-deep-uv-raman-spectrometer/">www.oceaninsight.com</a></td>
</tr>
<tr>
<td>ODIN compact deep UV Raman spectrometer </td>
<td><a target="_blank" href="https://is-instruments.com/odin-deep-uv-raman-spectrometer/">is-instruments.com</a></td>
</tr>
<tr>
<td>Pro-Raman-L-Dual-G by Enwave Optronics, USA </td>
<td>[<a class="ref" href=bibliography.html#Frühmann_2018>Frühmann_2018</a>]</td>
</tr>
</table>
</div>
<div id="Cases">
<p class="thema">Case Studies</p>
<table>
<tr>
<th>Object studied</th>
<th>Tasks and procedure </th>
<th>Source</th>
</tr>
<tr>
<td>Drawing attributed to Botticelli, Biblioteca Classense, Ravenna, Italy. </td>
<td>The goal of the work was determination of the elemental composition of azurite and lazurite based pigments. In this drawing, the blue tone of the sky changed from a darker hue of the upper area to a greenish blue in the lower area. This variation visually suggested that more than one single color was used. With 514.5 nm excitation, micro-Raman analysis revealed the presence of lazurite in all the examined zones of the sky with a clear and unmistakable Raman spectrum. Micro-Raman spectra of the same points in the blue areas of the drawing, excited using red light at 647 nm, indicated the presence of lead oxides, suggesting that massicot (orthorhombic lead monoxide, PbO) had been added to the blue color to obtain the desired shading. The presence of massicot justified the increase in the quantity of lead observed in passing from the darker upper areas of the sky to the lower ones, where a greenish shade was observable. </td>
<td>[<a target="_blank" href="bibliography.html# "> </a>] </td>
</tr>
<tr>
<td>Drawing “Trionfo d’Amore” attributed to Botticelli, Biblioteca Classense, Ravenna, Italy </td>
<td>The goal of this scientific work was the chemical characterisation of the main colours of precious drawing using non-destructive techniques (<a class="black" href="https://cvertan.github.io/physics4dh.github.io/M42_2_PIXE.html" target="_blank">PIXE</a> and micro-Raman spectroscopy) to avoid any deterioration of the artwork itself. The spectra have been collected using excitation wavelengths of 632.8 nm from a He-Ne laser (particularly suited for red brownish and yellow coloured samples) and of 514.5 nm from an Ar<a class="super">+</a>-ion laser (more appropriate for green to blue coloured samples). </td>
<td>[<a target="_blank" href="bibliography.html# "> </a>]</td>
</tr>
<tr>
<td>Egyptian polychrome cartonnage pigments </td>
<td>Raman spectroscopy was used to identify the minerals associated with the pigments. This technique confirmed the presence of cinnabar (α-HgS) in the red part of the fragments. A mixture of orpiment (As<a class="sub">2</a>S<a class="sub">3</a>) and bonazziite (β-As<a class="sub">4</a>S<a class="sub">4</a>) and/or alacránite (As<a class="sub">8</a>S<a class="sub">9</a>) was detected in the yellow regions of the fragments. The orange pigment was confirmed to be a mixture of orpiment, uzonite (χ-As<a class="sub">4</a>S<a class="sub">5</a>), and pararealgar (As<a class="sub">4</a>S<a class="sub">4</a>). Egyptian blue (CaCuSi<a class="sub">4</a>O<a class="sub">10</a>) and Egyptian green ((Cu,Ca)SiO<a class="sub">3</a>) pigments were detected from blue/green dark-colored regions of the fragments. </td>
<td>[<a target="_blank" href="bibliography.html# "> </a>]</td>
</tr>
<tr>
<td>Codex Vindobonensis slavicus 8, fol. 74v, written in 1368 by Prince Novak of Krbava (Croatia), Glagolitic manuscript, Austrian National Library (ÖNB) </td>
<td>The main aim of our analysis was to identify the illuminations’ pigments, the binding media, and the inks used for the script. The measurements were carried out <i>in situ</i> with excitation sources of diode lasers at 785 nm (~350 mW) and 532 nm (~50 mW) with narrow line-widths of 2.0 cm<a class="super">-1</a> and 1.5 cm<a class="super">-1</a>, respectively. Using an objective lens with 40x magnification, the spot size is about 50 μm in diameter for the 785 nm laser, whereas for the 532 nm laser the spot size reduces to 35 μm. The spectra were evaluated by comparing with an ISTA reference database. </td>
<td>[<a target="_blank" href="bibliography.html# "> </a>]</td>
</tr>
</table>
<p> </p>
<p> </p>
<p class="acknow">Acknowledgements:
[<a class="ref" href=bibliography.html# > </a>],
[<a class="ref" href=bibliography.html# > </a>],
[<a class="ref" href=bibliography.html# > </a>],
[<a class="ref" href=bibliography.html#wiki>wiki</a>],
[<a class="ref" href=bibliography.html# > </a>],
[<a class="ref" href=bibliography.html# > </a>],
[<a class="ref" href=bibliography.html# > </a>],
[<a class="ref" href=bibliography.html# > </a>],
[<a class="ref" href=bibliography.html# > </a>].</p>
<p class="important">More on subject: <a href="https://www.youtube.com/watch?v=VKV6L0wQMm4">www.youtube.com</a>, <a href="https://www.youtube.com/watch?v=b_7M3Vrzo18">www.youtube.com</a>, <a href="https://www.youtube.com/watch?v=Qs_xG8elHqA">www.youtube.com</a>
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