An [FeIII34] Molecular Metal Oxide

The dissolution of anhydrous iron bromide in a mixture of pyridine and acetonitrile, in the presence of an organic amine, results in the formation of an [Fe₃₄] metal oxide molecule, structurally characterised by alternate layers of tetrahedral and octahedral Fe^III ions connected by oxide and hydroxide ions. The outer shell of the complex is capped by a combination of pyridine molecules and bromide ions. Magnetic data, measured at temperatures as low as 0.4 K and fields up to 35 T, reveal competing antiferromagnetic exchange interactions; DFT calculations showing that the magnitudes of the coupling constants are highly dependent on both the Fe‐O‐Fe angles and Fe?O distances. The simplicity of the synthetic methodology, and the structural similarity between [Fe₃₄], bulk iron oxides, previous Fe^III–oxo cages, and polyoxometalates (POMs), hints that much larger molecular Fe^III oxides can be made.     

Electromagnetic moments of the doubly closed shell ±1 nucleon nuclei and on-line nuclear polarization

Electromagnetic moments of doubly closed shell ±1 nucleon nuclei were studied. Recent technical developments of the β-NMR was shown that was applicable for the polarized β emitters. Also, the implication of those new moments were discussed especially on the nuclear interactions and non nucleonic degrees of freedom.     

Beta-polarization measurements in solids

Experimental developments recently made in the beta-NMR measurements are reviewed. For production of polarized beta-emitters, the tilted foil technique has been successfully combined with the NMR. The low- and intermediate-energy heavy-ion reactions were recently found to be another sources of polarized beta-emitters. To achieve wide applicability of the NMR technique to nuclei far from stability, the tilted foil technique and the projectile fragmentation process in high-energy heavy-ion collisions were recently combined with the beta-NMR technique in the fragment separator built at the LBL.     

Multisupergravity from latticized extra dimension

The construction of the linearized four-dimensional multisupergravity from five-dimensional linearized supergravity with discretized fifth dimension is presented. The one-loop vacuum energy is evaluated when (anti)periodic boundary conditions are chosen for (bosons) fermions, respectively, or vice versa. It is proposed that the relation between discretized M-theory and strings may be found in the same fashion.     

Spatial profile measurement of electron number densities and analyte line intensities in an inductively coupled plasma

A versatile instrument for spatial profile measurement has been developed and applied to the measurement of electron number densities and analyte emission intensities in an inductively coupled plasma (ICP). A precise Y-Z stage on which the ICP source was mounted was set on a rail-based optical bench. By translating the ICP source with a precision of ± 0.01 mm, the H_β Stark broadening and analyte line intensities were measured with the use of a silicon intensified target (SIT) and a photomultiplier (PMT). Micro-computer assisted data acquisition allowed it to measure a large number of emission profiles in a short period. The ease of acquisition enabled to build up complete contour maps of electron number densities, Ca neutral atom (Ca I) and Ca ion (Ca II) line intensities, and intensity ratios of the Ca II and Ca I lines. The maximum electron number density was 4 × 10¹⁵ cm^?3 occurring low in the plasma and 5 mm off axis. In a contour map of the electron number densities a hollow region was found low in the plasma, and the distribution pattern looked like a deep “trench”. Along the central channel of the ICP, the peak position of Ca II emission occurred higher than that of Ca I emission, and the spatial distribution of Ca II emission was wider and taller than that of Ca I emission. It has been verified that Ca I is emitted mainly at the region where the electron number density is less than 1 × 10¹⁴ cm^?3.     

NMR studies on polarized12B implanted in highly oriented pyrolytic graphite

NMR measurements on¹²B nuclei implanted in a thin sheet of highly oriented pyrolytic graphite (Grafoil) have been made to study the magnitude of the polarization of¹²B and its electric quadrupole coupling. The magnitude of the residual polarization of¹²B held in carbon material is of crucial importance to the experiment measuring the average polarization of¹²B produced in the muon capture by¹²C. It was found that the polarization of¹²B can be maintained at 101.0±2.2% in Grafoil under a magnetic field of 3 kG. The electric quadrupole coupling was determined to bee ² qQ/h=+1207.3±8.2 kHz. From the magnitude and the sign of the electric field gradienteq, the location of¹²B was found to be a substitutional site in the carbon lattice. The anomalous B-C bond involving thesp ₂ hybrid orbitals with partially filledp _z electrons is also discussed.     

Atomic and nuclear polarization by beam-foil spectroscopy

Induction of atomic and nuclear polarization by grazing-incidence collisions (scattering) and by the tilted-foil interaction (transmission) is discussed. By direct observation of asymmetric Β decay, the foil can become a practical nuclear polarizer.