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Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons.The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the spins excited are those of the electrons instead of the atomic nuclei.
Pulsed electron paramagnetic resonance (EPR) is an electron paramagnetic resonance technique that involves the alignment of the net magnetization vector of the electron spins in a constant magnetic field. This alignment is perturbed by applying a short oscillating field, usually a microwave pulse.
Free electrons possess electric charge and magnetic moment whose absolute value is about one Bohr magneton.. The standard electron spin resonance, also known as electron paramagnetic resonance (EPR), is due to the coupling of electron magnetic moment to the external magnetic field through the Hamiltonian = describing its Larmor precession.
In physics, biology and chemistry, electron magnetic resonance (EMR) is an interdisciplinary field that covers both electron paramagnetic resonance (EPR, also known as electron spin resonance – ESR) and electron cyclotron resonance (ECR). [1]
Electron paramagnetic resonance (EPR) is a technique that allows the detection of free radicals formed in chemical or biological systems. In addition, it studies the symmetry and electronic distribution of paramagnetic ions. This is a highly specific technique because the magnetic parameters are characteristic of each ion or free radical. [15]
An EPR spectrometer used for spin-trapping technique. Spin trapping is an analytical technique employed in chemistry [1] and biology [2] for the detection and identification of short-lived free radicals through the use of electron paramagnetic resonance (EPR) spectroscopy.
Electron paramagnetic resonance (EPR) spectroscopy is dedicated to researching substances with unpaired electrons. It was first introduced in 1944, approximately the same time as a similar phenomenon - nuclear magnetic resonance (NMR). [10] [11] Owing to hardware and software limitations, EPR was not developing as rapidly as NMR. This led to a ...
For example, one can exert a kind of "torque" on an electron by putting it in a magnetic field (the field acts upon the electron's intrinsic magnetic dipole moment—see the following section). The result is that the spin vector undergoes precession, just like a classical gyroscope. This phenomenon is known as electron spin resonance (ESR).