Effect of X-Ray Radiation on the Valence State of Europium in Y2O3:Eu3+ Phosphor

Sensing the Spin State of Room-Temperature Switchable Cyanometallate Frameworks with Nitrogen-Vacancy Centers in Nanodiamonds

“…Upon illumination, a signal appeared at g = 2.03, consistent with prior observations by Cai et al (see Figure B) . Similar EPR profiles of Eu complexes have been reported. , …”

“…The movement of a largely orbital dominant moment in Fe III to the spin RO + • R radical, as well as the room-temperature moment on the Eu III ion interacting with the RO + • R radical could affect the NV – sensing contrast. Moreover, evidence for hyperfine structure in the EPR spectrum of the illuminated state (Figure B), observed for similar systems in previous reports, , suggests coupling between the RO + • R radical and spin active nuclei, such as 151 Eu (47.8%) and 153 Eu (52.2% abundance) both with 5 / 2 nuclear spin, which could increase the importance of the nuclear spin-bath interactions with NV – centers. , Although the detailed mechanism underlying photoinduced contrast reduction remains unclear, our conjecture is analogous to spin-noise mediated reduction in NV – relaxation times reported for other chemical systems in the literature. ,, Contrast reduction was also shown to be dependent on the illumination time (Figure S18), similar to the evolution of the IR spectrum observed by Cai et al . To probe the reversibility of this phototransformation, illuminated microcrystals of 2a on a TEM finder grid were annealed (2 h at 80 °C on a hot plate in an Al-foil-lined Petri dish in air) .…”

“…5 Similar EPR profiles of Eu complexes have been reported. 5,43 Photomagnetism�Surface Measurements in Compounds 2a and 2b. To investigate the presence of photomagnetism at the surface of particles of 2a, XPS analysis was conducted for both as-synthesized and illuminated crystalline powders.…”