title: ESR spectrometer with a loop-gap resonator for cw and time resolved studies in a superconducting magnet.
abstract: The design and performance of an electron spin resonance spectrometer operating at 3 and 9 GHz microwave frequencies combined with a 9-T superconducting magnet are described. The probehead contains a compact two-loop, one gap resonator, and is inside the variable temperature insert of the magnet enabling measurements in the 0-9T magnetic field and 1.5-400 K temperature range. The spectrometer allows studies on systems where resonance occurs at fields far above the g approximately 2 paramagnetic condition such as in antiferromagnets. The low quality factor of the resonator allows time resolved experiments such as, e.g., longitudinally detected ESR. We demonstrate the performance of the spectrometer on the NaNiO2 antiferromagnet, the MgB2 superconductor, and the RbC60 conducting alkaline fulleride polymer.
authors.affiliation: Budapest University of Technology and Economics, Physics and Solids in Magnetic Fields Research Group of the Hungarian Academy of Sciences, P.O. Box 91, H-1521 Budapest, Hungary. fsimon@ap.univie.ac.at
authors.forename: Ferenc
authors.initials: F
authors.lastname: Simon
authors.forename: Ferenc
authors.initials: F
authors.lastname: Murányi