Construction and Characterization of a Frequency-Controlled, Picometer-Resolution, Displacement Encoder-Actuator

We have constructed an actuator/encoder whose generated displacement is controlled through the resonance frequency of a microwave cavity. A compact, 10-micrometer-range, digitally-controlled actuator executing frequency-coded displacement with picometer resolution is described. We consider this approach particularly suitable for metrologic-precision scanning probe microscopy.Comment: 4 pages, 4 figure

Demonstration of NV-detected ESR spectroscopy at 115 GHz and 4.2 T

High frequency electron spin resonance (ESR) spectroscopy is an invaluable tool for identification and characterization of spin systems. Nanoscale ESR using the nitrogen-vacancy (NV) center has been demonstrated down to the level of a single spin. However, NV-detected ESR has exclusively been studied at low magnetic fields, where spectral overlap prevents clear identification of spectral features. Within this work, we demonstrate NV-detected ESR measurements of single-substitutional nitrogen impurities in diamond at a NV Larmor frequency of 115 GHz and the corresponding magnetic field of 4.2 Tesla. The NV-ESR measurements utilize a double electron-electron resonance sequence and are performed using both ensemble and single NV spin systems. In the single NV experiment, chirp pulses are used to improve the population transfer and for NV-ESR measurements. This work provides the basis for NV-based ESR measurements of external spins at high magnetic fields

Microwave cavity perturbation technique. Part 2, Experimental scheme

In this paper, the second in a three part series, we describe an experimental scheme used to measure the electrodynamical response of a material in the millimeter wave range of frequency. In particular, with this technique we can directly evaluate the complex conductivity from a measurement ofboth the bandwidth and characteristic frequency of a resonator containing the specimen. We will describe in detail all the technical improvements achieved which provide the required accuracy

Partial separation of fullerenes by gradient sublimation

An experimental technique is investigated to separate/enrich fullerenes or metallofullerenes, exploiting differences in sublimation temperatures without the use of solvents. Fullerenes are sublimed out of the soot and deposited on a quartz rod along a temperature gradient (gradient sublimation). In a position-sensitive experiment the composition of the deposit on the rod is monitored by laser-desorption mass spectrometry. Strongly enriched regions containing specific fullerene molecules (i.e., C84 or La@ C82) are observed. Furthermore, C74, which could not be extracted from the soot by organic solvents, sublimes out of the soot

Synthesis of hydroazafullerene C59HN, the parent hydroheterofuIlerene

The electronic and geometric properties of C60 can be perturbed by replacing one or more carbon atoms of the fullerene skeleton with an atom of a different element. Exchange of one carbon atom with nitrogen, a trivalent atom with a lone pair of electrons, produces the azafullerene radical C59N·, which is isoelectronic with the C60 radical anion. The process is slightly similar to doping silicon with phosphorus. We have previously described the synthesis of the azafullerene dimer; here we report the bulk preparation of the simplest azafullerene, C59HN. The electronic, vibrational and 13C NMR spectroscopic features of C59HN are similar to those of the dimer, except for the signature of the sp3 (C-H) carbon. C59HN should open the door to a new chemistry of heterofullerenes.

Synthesis of hydroazafullerene C59HN, the parent hydroheterofullerene

THE electronic and geometric properties of C-60 can be perturbed by replacing one or more carbon atoms of the fullerene skeleton with an atom of a different element. Exchange of one carbon atom with nitrogen, a trivalent atom with a lone pair of electrons, produces the azafullerene radical C59N; which is isoelectronic with the C-60 radical anion. The process is slightly similar to doping silicon with phosphorus(1). We have previously described the synthesis of the azafullerene dimer(2); here we report the bulk preparation of the simplest azafullerene, C59HN. The electronic, vibrational and C-13 NMR spectroscopic features of C59HN are similar to those of the dimer(2), except for the signature of the sp(3) (C-H) carbon. C59HN should open the door to a new chemistry of heterofullerenes