The Effect of Power Saturation on the Line Shapes of Nitroxide Spin Probes Under the Influence of Spin-Exchange and Dipole–Dipole Interactions Studied by CW EPR

Experimental Observation of a Peculiar Effect in Saturated Electron Paramagnetic Resonance Spectra Undergoing Spin Exchange. Magnetic Polariton?

“…For us, the most interesting is V disp /V pp because almost nothing is known. 16 Peculiar features that occur when the spectra collapse, A abs = 0, for V = V* are not accessible with 15PADS; therefore, we shall study 15PDT to higher values of V/γA 0 . The analytical expressions in ref 3 are still valid at V* and above.…”

“…8 The CWS of the amplitude of the DIS, V disp , was studied theoretically and experimentally for the first time earlier this year. 16 No theory prior to 2018 16 predicted the AHE. See Figure 1 for definitions of the important parameters.…”

“…The peculiarities in refs − are only significant when the spectra are both saturated and V is significant. Despite a large experimental and theoretical literature on saturation and likewise on HSE, there have been very few experimental investigations where both phenomena were significant and none of those addressed the presence of DIS until this year . No evidence of the AHE was uncovered in ref because that investigation was limited to low values of both V and H 1 .…”

“…In the recent paper, which studied both HSE and saturation taking into account DIS, the theory predicted AHE, however only as numerical results . The exciting feature of ref is that it provides analytical equations to describe the peculiar features of all of the measurable parameters.…”

“…There are analytical expressions for these quantities in ref ; see Table S1 of the SI for a brief description of the predicted results, which show that there are interesting behaviors of all four parameters, some of which may be studied at the modest values of V / γA 0 accessible with 15PADS. For us, the most interesting is V disp / V pp because almost nothing is known …”