EMR electron magnetic

EMR (electron magnetic resonance) See electron paramagnetic resonance spectroscopy. 

ESR include electron magnetic resonance (EMR) and electron paramagnetic resonance (EPR). ESR is more limited than NMR, since it can only be used to study species with one or more unpaired electron spins. Common examples of such species are the following ... 

Lanthanum strontium manganate, known also as LSM, is known for its magnetoresistance properties, and is also used in solid oxide fuel cells (SOFC). Sonochemistry was used for its preparation [121]. Electron magnetic resonance (EMR) spectra of nanosized sonochemically sintered powders of Lao.7Sro.3Mn03 (annealed, Tc = 340 K) were studied. 

This chapter reviews the work ofthe last five to six years on paramagnetic states of carotenoids using electron magnetic resonance. Mainly radical cation and neutral molecular triplet states are treated. Part of this ch te deals with paramagnetic states of carotenoids in model systems. These have been synthesized in order to mimic both electron and energy transfer processes in the natural photosynthetic systems. Consequently, the electron magnetic resonance (EMR) spectroscopy of carotenoid triplet and radical states yields important information about their photochemistry. Finally, the EMR spectroscopy on carotenoid radicals is reviewed. It serves to establish the database on their intrinsic properties which is necessary for the analysis of carotenoid radicals in vivo. 

EPR, also referred to as Electron Spin Resonance (ESR) or Electron Magnetic Resonance (EMR), is the only direct method to detect free radicals (ROS, reactive oxygen species) or other paramagnetic species. Bruker BioSpin offers routine research systems as well as the e-scan, a dedicated table-top EPR scanner... 

Electron spin resonance (ESR) spectroscopy is also known as electron paramagnetic resonance (EPR). spectroscopy or electron magnetic resonance (EMR) spectroscopy. The main requirement for observation of an ESR response is the presence of unpaired electrons. Organic and inorganic free radicals and many transition metal compounds fulfil this condition, as do electronic triplet state molecules and biradicals, semicon-ductor impurities, electrons in unfilled conduction bands, and electrons trapped in radiation-damaged sites and crystal defect sites. 

No commercial electron magnetic resonance spectrometer presently operates continuously over one or more frequency octaves, but instead utilizes a narrow band source that is mechanically or electrically tunable over a 500-MHz range. Despite past arguments against their use, wideband solid-state devices perform competitively with traditional narrow band devices, and numerous synthesized frequency sources are continuously tunable from 2-26 GHz. The phase noise, rated at <-80 dBc at 10 kHz offset for many systems, is excellent, and comparable to narrow band reflex klystrons. Similarly, many components can be made broadband or at least octave spanning, and therefore the experimental capability is available. One approach that is economical relies on the VXIbus instrumentation architecture, which enables one to assemble a modular instrument on a common computer-controlled mainframe that allows experimental flexibility, and further details of a broadband EMR instrument may be found in Volume 21 of this series (Bender, 2004). 

At moderate to high magnetic fields (i.e., Ho 0. T), the electron Zeeman interaction dominates the EMR spectrum, which at its simplest may be described by a single transition hv=ge eHo, where ge and Pe are the so-called g-value and the Bohr magneton (A fundamental unit of the electron s magnetic moment, ettHtrie = 9.274 X 10 J T ), respectively. In atoms and molecules the g-value is replaced by a tensor and deviates from the scalar quantity of 2.0023 for a free electron. The... 

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