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Raman Spectroscopy
Raman spectroscopy () (named after physicist C. V. Raman) is a Spectroscopy, spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman spectroscopy is commonly used in chemistry to provide a structural fingerprint by which molecules can be identified. Raman spectroscopy relies upon inelastic scattering of photons, known as Raman scattering. A source of monochromatic light, usually from a laser in the visible spectrum, visible, near infrared, or ultraviolet, near ultraviolet range is used, although X-ray Raman scattering, X-rays can also be used. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Time-resolved spectroscopy and infrared spectroscopy typically yields similar y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raman Energy Levels
Raman may refer to: People *Raman (name) **C. V. Raman (1888–1970), Indian Nobel Prize-winning physicist **K. R. Narayanan, Kocheril Raman Narayanan, President of India from 1997 to 2002 Places * Raman, Bathinda, India * Raman, Rawalpindi, Pakistan * Raman district, Yala Province, Thailand ** Raman railway station * Raman oil field, in Batman, Turkey Other uses * Raman (crater), a lunar impact crater * Raman (film), ''Raman'' (film), a 2008 Indian Malayalam film * Raman scattering, a physical effect named after C. V. Raman * Raman spectroscopy, an analytical technique based on Raman Scattering * ''Raman'', a comic, and its title character, created by Pran Kumar Sharma See also * * Ramana (other) * Ramani (other) * Rahman (other) * Rama (other) * Ramen (other) * Rehman (other) * Ramman, or Hadad, a Canaanite storm and rain god {{Disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rayleigh Scattering
Rayleigh scattering ( ) is the scattering or deflection of light, or other electromagnetic radiation, by particles with a size much smaller than the wavelength of the radiation. For light frequencies well below the resonance frequency of the scattering medium (normal dispersion relation, dispersion regime), the amount of scattering is inversely proportional to the fourth power of the wavelength (e.g., a blue color is scattered much more than a red color as light propagates through air). The phenomenon is named after the 19th-century British physicist Lord Rayleigh (John William Strutt). Rayleigh scattering results from the electric polarizability of the particles. The oscillating electric field of a light wave acts on the charges within a particle, causing them to move at the same frequency. The particle, therefore, becomes a small radiating dipole whose radiation we see as scattered light. The particles may be individual atoms or molecules; it can occur when light travels throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonid Isaakovich Mandelstam
Leonid Isaakovich Mandelstam or Mandelshtam ( rus, Леонид Исаакович Мандельштам, p=lʲɪɐˈnʲit ɨsɐˈakəvʲɪtɕ mənʲdʲɪlʲˈʂtam, a=Ru-Leonid_Mandelstam.ogg, links=y; 4 May 1879 – 27 November 1944) was a Soviet and Russian physicist. Life Leonid Mandelstam was born in Mogilev, Russian Empire (now Belarus) into a Jewish family. He studied at the Novorossiya University in Odesa, but was expelled in 1899 due to political activities, and continued his studies at the University of Strasbourg. He remained in Strasbourg until 1914, and returned with the beginning of World War I. He was awarded the Stalin Prize in 1942. He died in Moscow, aged 65. Scientific achievements The main emphasis of his work was broadly considered theory of oscillations, which included optics and quantum mechanics. He was a co-discoverer of inelastic ''combinational scattering of light'' used now in Raman spectroscopy (see below). This paradigm-altering discovery ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grigory Landsberg
Grigory Samuilovich Landsberg (Russian: Григорий Самуилович Ландсберг; 22 January 1890 – 2 February 1957) was a Soviet physicist who worked in the fields of optics and spectroscopy. Together with Leonid Mandelstam he co-discovered inelastic combinational scattering of light, which is known as Raman scattering. Vitae Landsberg graduated from the Moscow State University in 1913 and then taught there from 1913 to 1915, 1923–1945, and 1947–1951 (Professor since 1923). From 1934, he simultaneously worked also in the Physical Institute of the Academy of Sciences of the USSR. From 1951 to 1957 he was a professor at the Moscow Institute of Physics and Technology. Landsberg conducted pioneering studies on the vibrational scattering of light in crystals beginning in 1926. In 1928, Landsberg and Mandelstam discovered a phenomenon of ''combinational scattering of light'' (this phenomenon became known as Raman scattering or the Raman effect independently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolf Smekal
Adolf Gustav Stephan Smekal (12 September 1895 – 7 March 1959) was an Austrian theoretical physicist, with interests in solid state physics,"The historical development of quantum theory", by Jagdish Mehra, Helmut Rechenbergp. 327, biographical note/ref> known for the prediction of the inelastic scattering of photons (the Raman effect).A. Smekal. 1943. Zur Quantentheorie der Dispersion. ''Die Naturwissenschaften'' 11(43): 873-875 . Adolf Smekal studied at the Vienna College of Technology (1912–1913), received his doctorate from the University of Graz (1913–1917), and then studied at the University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ... (1917–1919). References {{DEFAULTSORT:Smekal, Adolf 1895 births 1959 deaths Austrian physicists TU Wien a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tip-enhanced Raman Spectroscopy
Tip-enhanced Raman spectroscopy (TERS) is a variant of surface-enhanced Raman spectroscopy (SERS) that combines scanning probe microscopy with Raman spectroscopy. High spatial resolution chemical imaging is possible ''via'' TERS, with routine demonstrations of nanometer spatial resolution under ambient laboratory conditions, or better at ultralow temperatures and high pressure. The maximum resolution achievable using an optical microscope, including Raman microscopes, is limited by the Abbe limit, which is approximately half the wavelength of the incident light. Furthermore, with SERS spectroscopy the signal obtained is the sum of a relatively large number of molecules. TERS overcomes these limitations as the Raman spectrum obtained originates primarily from the molecules within a few tens of nanometers of the tip. Although the antennas' electric near-field distributions are commonly understood to determine the spatial resolution, recent experiments showing subnanometer-resolved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonance Raman Spectroscopy
Resonance Raman spectroscopy (RR spectroscopy or RRS) is a variant of Raman spectroscopy in which the incident photon energy is close in energy to an electronic transition of a compound or material under examination. This similarity in energy (resonance) leads to greatly increased intensity of the Raman scattering of certain vibrational modes, compared to ordinary Raman spectroscopy. Resonance Raman spectroscopy has much greater sensitivity than non-resonance Raman spectroscopy, allowing for the analysis of compounds with inherently weak Raman scattering intensities, or at very low concentrations. It also selectively enhances only certain molecular vibrations (those of the chemical group undergoing the electronic transition), which simplifies spectra. For large molecules such as proteins, this selectivity helps to identify vibrational modes of specific parts of the molecule or protein, such as the heme unit within myoglobin. Resonance Raman spectroscopy has been used in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Enhanced Raman Spectroscopy
Surface-enhanced Raman spectroscopy or surface-enhanced Raman scattering (SERS) is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on rough metal surfaces or by nanostructures such as plasmonic-magnetic silica nanotubes. The enhancement factor can be as much as 1010 to 1011, which means the technique may detect single molecules. History SERS from pyridine adsorbed on electrochemically roughened silver was first observed by Martin Fleischmann, Patrick J. Hendra and A. James McQuillan at the Department of Chemistry at the University of Southampton, UK in 1973. This initial publication has been cited over 6000 times. The 40th Anniversary of the first observation of the SERS effect has been marked by the Royal Society of Chemistry by the award of a National Chemical Landmark plaque to the University of Southampton. In 1977, two groups independently noted that the concentration of scattering species could not account for the enhanced signal and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fourier Transform Spectroscopy
Fourier-transform spectroscopy (FTS) is a measurement technique whereby Spectrum (physics), spectra are collected based on measurements of the coherence (physics), coherence of a Radiation, radiative source, using time-domain or space-domain measurements of the radiation, electromagnetic radiation, electromagnetic or not. It can be applied to a variety of types of ''spectroscopy'' including optical spectroscopy, infrared spectroscopy (Fourier-transform infrared spectroscopy, FTIR, FT-NIRS), Nuclear Magnetic Resonance Spectroscopy, nuclear magnetic resonance (NMR) and magnetic resonance spectroscopic imaging (MRSI), mass spectrometry and electron spin resonance spectroscopy. There are several methods for measuring the temporal coherence of the light (see: Optical autocorrelation#Field autocorrelation, field-autocorrelation), including the continuous-wave and the pulsed Fourier-transform spectrometer or Fourier-transform spectrograph. The term "Fourier-transform spectroscopy" refl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
