Spin current and electrical polarization in GaN double-barrier structures

Tunnel spin polarization in a piezoelectric AlGaN/GaN double barrier structure is calculated. It is shown that the piezoelectric field and the spontaneous electrical polarization increase an efficiency of the tunnel spin injection. The relation between the electrical polarization and the spin orientation allows engineering a zero magnetic field spin injection manipulating the lattice-mismatch strain with an Al-content in the barriers.Comment: 13 pages, 6 figure

Weak antilocalization and zero-field electron spin splitting in AlGaN/AlN/GaN heterostructures with a polarization induced two-dimensional electron gas

Spin-orbit coupling is studied using the quantum interference corrections to conductance in AlGaN/AlN/GaN two-dimensional electron systems where the carrier density is controlled by the persistent photoconductivity effect. All the samples studied exhibit a weak antilocalization feature with a spin-orbit field of around 1.8 mT. The zero-field electron spin splitting energies extracted from the weak antilocalization measurements are found to scale linearly with the Fermi wavevector with an effective linear spin-orbit coupling parameter 5.5x10^{-13} eV m. The spin-orbit times extracted from our measurements varied from 0.74 to 8.24 ps within the carrier density range of this experiment.Comment: 16 pages, 4 figure

The Experimental WSN Network for Underground Monitoring H2 Abundance in the Mine Atmosphere Karnasurt Mine Lovozero Layered Alkaline Intrusion

We have developed specialized equipment based on mini-MDM hydrogen sensors and the WSN telecommunication technology for long-term monitoring of hydrogen content in the environment. Unlike existing methods, the developed equipment makes it possible to carry out measurements directly in the explosion zone with high discreteness in time. This equipment was tested at a large rare-earth deposit of the Lovozero Alkaline Pluton Karnasurt in the underground mining tunnel. We observed a short time very high concentration of hydrogen in the atmosphere (more than 3 orders of normal atmosphere concentration). This discovery is very important because at the time of the explosion one can create abnormally high concentrations of explosive mixtures of hydrocarbon gases that can lead to accidents. The high resolving power of the measurement equipment makes it possible to determine the shape of the anomaly hydrogen of such a concentration and to calculate the volumes of hydrogen released from the rocks, at first time in the practice. The shape of the anomaly usually consists of 2-3 additional peaks of the shape - "dragon-head-like peak". We make an first attempt is made to explain this form of anomaly in the article. The aim of the work in the estimation hydrogen emission in mining ore deposit rare earth elements

The reactions of 2H-1,2,3-diazaarsoles with phenyl azide

2-Phenyl-5-methyl- and 2,5-diphenyl-2H-1,2,3-diazaarsoles 1a,b react with phenyl azide to give several crystalline products: tricyclic derivatives 2a,b and 4,4′-bis(2H-1,2,3-diazaarsoles) 5a,b formed at room temperature, and a cycloadduct 6a obtained at + 4°C. Compound 6a undergoes a fast rearrangement in solutions of Et3N or pyridine to give a stable dicoordinate arsenic compound, the 2H-1,2,3-diazaarsole 7a. Heating solutions of 2a under reflux in an inert atmosphere leads to 5a and of 2b, in the presence of water, to 4b. The structures of 2a, 4b, and 7a were characterized by X-ray crystal structure determinations. © 1996 John Wiley & Sons, Inc

Molecular and crystal structure of 6-methyl-3-methoxy-2, 4,4-triphenyl-3-phenylimino-2,3,4,5-tetrahydro-1, 2,3-diazaphosphorine and 3-anilino-6-methyl-3-oxo-2,4, 4-triphenyl-2,3,4,5-tetrahydro-1,2,3-diazaphosphorine

1. 6-Methyl-3-methoxy-2,4,4-triphenyl-3-phenylimino-2,3,4,5-tetrahydro-1,2,3-diazaphosphorine exists as the monomer in the crystalline state. 2. The crystal and molecule structure of the tetrahydrodiazaphosphorine and its solvate with CH3OH added at the P=N bond was determined. © 1983 Plenum Publishing Corporation

Molecular and crystal structure of a product of the reaction of 5-methyl-2-phenyl-1,2,3-diazaphosphol with diazopropane

X-ray diffraction structural analysis established the structure of 2,2,6-trimethyl-1-oxo-1-hydro-4-phenyl-8-[α-phenylhydrazono]ethyl-4,5-diaza-1,3-diphosphabicyclo[3.3.03,7]oct-5-ene, in which a long conjugation chain is realized through the hydrazone group and the adjacent atoms. © 1984 Plenum Publishing Corporation

Molecular structure of cis-syn-cis isomer of 2,2,6,9-tetramethyl-4,11-diphenyl-4,5,10,11-tetraaza-1,3-diphosphatricyclo[6.3.0.03,7]undeca-5, 9-diene

It has been shown by x-ray structure analysis that the interaction of 2-phenyl-5-methyl-1,2,3-diazophosphole with diazopropane forms, along with the cis-anti-cis isomer, the cissyn-cis isomer of 2,2,6,9-tetramethy1-4,11-dipheny1-4,5,10,11-tetraaza-1,3-diphosphatricyclo-[6.3.0.03,7]undeca-5,9-diene. © 1985 Plenum Publishing Corporation

Synthesis and molecular structure of 2,2,6,9-tetramethyl-4, 11-diphenyl-4,5,10,11-tetraaza-1,3-diphosphatricyclo[6.3.0.03,7] undeca-5,9-diene

1. The reaction of 2-phenyl-5-methyl-1,2,3-diazaphosphole with diazapropane yields the first example of the cycloaddition of a phosphorus diylide at the dicoordinated phosphorus P=C bond. 2. X-ray structural analysis unequivocally indicated the structure of the product of this reaction and gave its molecular geometry. © 1983 Plenum Publishing Corporation