Right-angle wiggling electron paramagnetic resonance spectroscopy

Abstract

Articles you may be interested inNovel multisample dielectric resonators for electron paramagnetic resonance spectroscopy Rev. Sci. Instrum. 81, 044702 (2010); 10.1063/1.3378287 A modification of the commercial ESR900 cryostat to enable three-dimensional electron-paramagneticresonance studies of crystals Rev. Sci. Instrum. 79, 046107 (2008); 10.1063/1.2908163Advantages of superconducting quantum interference device-detected magnetic resonance over conventional high-frequency electron paramagnetic resonance for characterization of nanomagnetic materials Right-angle wiggling ͑RAW͒ electron paramagnetic resonance ͑EPR͒ spectroscopy is introduced. In this two-dimensional pulse EPR technique the orientation of the external magnetic field B 0 is varied during the pulse sequence. For this purpose an additional sinusoidal field of variable amplitude ⌬B 0 Ќ is applied perpendicular to the orientation of B 0 . RAW-EPR is an alternative and experimentally much less demanding technique to right-angle spinning for performing anisotropy-resolved EPR experiments ͓Sierra and Schweiger, Mol. Phys. 95, 973 ͑1998͔͒. It can be applied to improve the resolution of EPR spectra of orientationally disordered systems or to separate overlapping single-crystal EPR spectra, and to facilitate an unambiguous interpretation of these spectra. A detailed theoretical description of RAW-EPR is given. Model calculations for systems with axial and orthorhombic symmetry, as well as a number of RAW-EPR experiments on paramagnetic systems with anisotropic interactions are presented.

Defect structure and formation of defect complexes in Cu2+-modified metal oxides derived from a spin-Hamiltonian parameter analysis

“…Owing to the square-planar oxygen coordination, such compounds may serve as model substance with a pseudo (V O − Cu − V O ) defect complex. The corresponding EPR spectra of bis(salicylaldoximato)Cu(II), Cu(sal) 2 , diluted into a Ni(sal) 2 powder [42][43][44] and bis(acetylacetonato)Cu(II), Cu(acac) 2 , diluted into a Pd(acac) 2 matrix [45,46] are depicted in figure 2(i,ii). For these compounds, a considerably increased A Cu -hyperfine splitting and slightly reduced g -value are observed.…”

Characterization of the high-spin Mn 2 + -functional centre in BaTiO_3 by means of right-angle wiggling electron paramagnetic resonance spectroscopy

“…On the one-hand side, the magnitude of the external magnetic field is varied in the sotermed electron-Zeeman (EZ) resolved EPR experiment [1,2], where the second dimension represents the electron g-value. On the other hand, the orientation of the external field may be altered by means of the right angle wiggling (RAW) EPR technique [3,4]; an alternative, and technically less demanding method as compared to the formerly introduced right-angle spinning (RAS) EPR technique [5,6]. Both methods provide a means for disentangling complicated EPR spectra.…”

Cryogenic Q-band (35GHz) probehead featuring large excitation microwave fields for pulse and continuous wave electron paramagnetic resonance spectroscopy: Performance and applications

“…This intersection centers the quartz sample tube precisely in the sample loop (d 0 ) of the LGR, allows sample exchange at all temperatures, connects the sample access tube to the LGR housing and adds additional mechanical stability. It serves also to fix the 100 kHz B 0 -field modulation Helmholtz coil (not visible) used in CW-EPR, NZ-ESEEM [12], EZ-EPR [29], and AR-EPR [30], experiments which are ideally implemented with the small size (down-scaled) 35 GHz LGRs.…”

“…All three resonators described above are suitable for performing twodimensional EPR experiments. With the BLGR and the DR, experiments using rf fields and field modulations and jumps, such as ENDOR, nuclear-Zeeman resolved ESEEM (NZ-ESEEM) [12], electron-Zeeman resolved EPR (EZ-EPR) [29], anisotropic resolved EPR (AR-EPR) [30], and longitudinal detection EPR [31], are performed with high sensitivity.…”