Hydrogen shallow donors in undoped and doped ZnO systems have been studied by means of the electron paramagnetic resonance and nuclear magnetic resonance measurements. Experimental evidence is given in this work for coupling of hydrogen shallow donors and Mn ions in Mn-doped ZnO mediating short-range ferromagnetic spin-spin interaction.
Dodecylamine-intercalated vanadium oxide nanotubes were obtained by distinct synthesis processes. Water intercalation in the nanotube structure was identified in a marked manner by the distortion of the VO x layers in the x-ray diffraction patterns and enhanced V 4+v O absorption in the Fourier-transform infrared spectra. Our electron spin resonance measurements sensitively reflect changes in the microscopic structure and magnetic interactions introduced by the water intercalation in the vanadium oxide nanotubes.
Room-temperature ferromagnetism in proton-irradiated C60 fullerene is demonstrated. The ferromagnetism turns into diamagnetism intrinsic to the fullerene as the magnetic field increases above a critical field.
Electrical conductivity and photoconductivity measurements were carried out on vanadium dioxide (VO2) nanorods prepared by the hydrothermal treatment of vanadium pentoxide gels. While the structural properties of the nanorods resembled those of the Cr-doped VO2, the charge and spin dynamics appears to resemble those of the Nb-doped VO2. The magnetic and (photo)electrical properties of the nanorods can be understood in terms of localization of itinerant electrons giving rise to a spin-polarized (S=3/2) V4+ pair, dominant at higher temperatures, or to a (S=1) V3+ ion out of a V4+ ion pair, dominant at lower temperatures.
Electron spin resonance measurements of proton-irradiated graphite have revealed detailed nature of proton-irradiation-induced defects. Our results indicate that proton-irradiation creates confined defect regions of a metallic island surrounded by an insulating magnetic region which “isolates” the metallic island inside from the metallic graphite background outside. We have thus come up with a picture of phase separation in proton-irradiated graphite comprising three regions of distinct electrical and magnetic properties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.