Optically detected magnetic resonance ODMR studies

Optically detected magnetic resonance (ODMR) studies of -iT-conjugated polymer-based hght emitting diodes (LEDs) J. Shinar Organic Electroluminescent Materials and Devices, S. Miyata and H.S. Nalwa, Eds., Gordon and Breach, Amsterdam, pp.177-202... 

Optically Detected Magnetic Resonance (ODMR) Studies of Ti-conjugated Polymer Films, Solutions, Blends, and Devices... 

Optically detected magnetic resonance (ODMR) studies of 7i-conjugated polymer films, solutions, blends and devices... 

The charged quasiparticles can be probed by electrical dc conductivity measurements (for polarons), magnetic susceptibility (for polarons and bipolarons), electron-spin resonance (ESR) (for polarons) and optical measurements (for polarons and bipolarons). As ESR is well suited for studying spin-carrying polarons, optical modification of the ESR (optically detected magnetic resonance ODMR) can be applied to link the emissive or absorbing properties of the polymer with its spin state. 

E.S.R. and Microwave Studies and Related Studies.—The recently demonstrated technique of triplet absorption detection of magnetic resonance (tadmr) has been used to determine intersystem crossing from individual spin levels of PH, ]- and [2H10]-anthracene and 3,4-benzpyrene triplets.22 Optically detected magnetic resonance (odmr) has been used to probe out-of-chain hopping of excitons in... 

Another crucial finding was the realization that rapid spin-lattice (Ti) relaxation in the high-symmetry cycloalkane radical cations precludes their detection with optically-detected magnetic resonance (ODMR) [39-48], the technique which was routinely used to study radical cations in radiolysis of hydrocarbons [38, 50]. For example, trans-decalin + isolated in room-temperature cyclohexane has Tj 7 ns [50] while typical solute radical cations have Ti 1 ps. Since it takes several tens of nanoseconds to flip the electron spin with the microwave radiation (which is required for the magnetic resonance detection) radical cations of some cycloalkanes cannot be detected by ODMR. 

Hess [77] prepared this polymer and studied its photoluminescence, optically detected magnetic resonance (ODMR) and nonresonant magnetic field effects. 

Optically-detected magnetic resonance spectroscopy (ODMR) has been used to study the chlorophyll triplet state. Clarke et al.40) utilized an apparatus combining a pair of argon lasers with a microwave spectrometer. Preliminary results are dedicated to determinate structural dynamical features of chlorophyll in vivo. In such experiments the chlorophyll triplet state can be considered as a paramagnetic probe for the surroundings and interactions within the photosynthetic systems40. ... 

Electrically detected magnetic resonance (EDMR) is conceptually similar to ODMR, i.e. the magnetic resonance is observed through spin-dependent electrical rather than optical properties of a sample. Virtually all of the EDMR in GaN-based materials reported to date has bear performed on LEDs and so the device type will serve as a basis for the organisation of this section. Three basic device types have been studied m-i-n-n+ diodes, double heterostructures (DHs) and single quantum wells (SQWs). Some details on these structures can be found elsewhere in this volume [35] and in the original work. 

There are many experimental techniques for the determination of the Spin-Hamiltonian parameters g, Ux, J. D, E. Often applied are Electron Paramagnetic or Spin Resonance (EPR, ESR), Electron Nuclear Double Resonance (ENDOR) or Triple Resonance, Electron-Electron Double Resonance (ELDOR), Nuclear Magnetic Resonance (NMR), occasionally utilizing effects of Chemically Induced Dynamic Nuclear Polarization (CIDNP), Optical Detections of Magnetic Resonance (ODMR) or Microwave Optical Double Resonance (MODR), Laser Magnetic Resonance (LMR), Atomic Beam Spectroscopy, and Muon Spin Rotation (/iSR). The extraction of data from the spectra varies with the methods, the system studied and the physical state of the sample (gas, liquid, unordered or ordered solid). For these procedures the reader is referred to the monographs (D). Further, effective magnetic moments of free radicals are often obtained from static... 

---