On-axis energy analysis of69Ga+, Ga2+, and Ga 2 + ions emitted from a gallium liquid metal ion source

On-axis energy distribution measurements of 3 ionic species emitted from a gallium liquid metal ion source are reported. Voltage deficits, FWHM energy spreads, angular intensities and chromatic angular intensities are presented and compared with other published work. Ga⁺ deficit variations with beam current and temperature are discussed in detail. Ga ₂ ⁺ FWHM and deficit changes with source operating conditions are accounted for by a model of droplet fragmentation.     

Raman scattering from GaAs-Al0.5Ga0.5As-AlAs polytype superlattices

We report the first Raman study of GaAs-Al_0.5Ga_0.5As-AlAs polytype superlattices grown by molecular-beam epitaxy. Folded longitudinal acoustic phonon modes were observed for all the samples. The frequencies agree well with those calculated using an elastic continuum model. The intensities of the folded modes have novel properties, compared with double-constituent superlattices like GaAs-(AlGa)As.     

The hyperfine structure anomalies of67Ga,69Ga,71Ga,72Ga,113In,115In,and117mIn

The ratios of theg _i -factors of⁶⁹Ga and⁷¹Ga and of¹¹³In and¹¹⁵In have been measured by the NMR method. Using hyperfine interaction constants from literature, the hyperfine structure anomalies⁶⁷Δ⁶⁹,⁶⁹Δ⁷¹,⁷¹Δ⁷² of gallium and¹¹³Δ¹¹⁵,¹¹⁵Δ^117m of indium in the² P _1/2 and² P _3/2 atomic ground states have been calculated.     

High-spin spectroscopy of 63 31Ga32 and 65 31Ga34

High-spin states in the nuclei ⁶³Ga and ⁶⁵Ga were studied following the reaction ³²S + ⁴⁰Ca at a reaction energy of 125 MeV and using the GASP γ-ray spectrometer in combination with the ISIS charged-particle detector system. In addition to low-lying negative-parity states with single-particle character, rotational-like cascades built on the 9/2⁺ and 19/2^- states have been observed in both nuclei. Sidebands with negative parity in ⁶³Ga and positive parity in ⁶⁵Ga could be established. The experimental results are compared with Total Routhian Surface calculations which describe the nuclei as moderately deformed (β₂≈ 0.25) and γ soft at low rotational frequencies. The highest experimentally observed positive-parity state in ⁶⁵Ga (41/2⁺) is in good agreement with the calculated crossing of the collective band with a non-collective one terminating at this spin. Received: 20 December 2000 / Accepted: 2 May 2001     

Energy levels and radiative rates for Ne-like ions from Cu to Ga

Energy levels, lifetimes and wave function compositions are computed for 127 fine structural levels in Ne-like ions (\(Z=29{-}31\)). Configuration interaction has been included among 51 configurations (generating 1016 levels) and multiconfigurational Dirac–Fock method is used to generate the wave functions. Similar calculations have also been performed using the fully relativistic flexible atomic code (FAC). Transition wavelength, oscillator strength, transition probabilities and line strength are reported for electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions from the ground level. We compared our calculated results with the available data in the literature. The calculated results are found to be in close agreement with the previous results. Further, we predict some new atomic data which may be important for plasma diagnostics.     

Relaxation rates of 69Ga and 71Ga nuclei in aqueous solutions

Line widths in the ⁶Li, ⁷Li, ²³Na, ³⁹K, ⁸⁵Rb, ⁸⁷Rb and ¹³³Cs N.M.R. spectra of solutions of the alkali salts of biphenyl and fluorenone are reported as a function of solvent and temperature. From a numerical analysis of the room temperature data the contribution of the various relaxation mechanisms to the line widths are established. It is shown that the results are consistent with the observed solvent and temperature dependence of the line widths. Values of the electron spin correlation time are obtained and a value of 1·6 ± 0·4 Å is found for the ‘Van der Waals radius’ of the biphenyl anion. Line width expressions for the static and the dynamic ion pair model are presented. It is demonstrated that the static ion pair model applies to solutions of caesium biphenylide. Semi-empirical rules are presented concerning the importance of various relaxation mechanisms for the different alkali nuclei in the type of solution studied here.     

Possible mixed valence behavior of CeIr2Ga and YbIr2Ga

We report possible mixed valence behavior in the new ternary compounds CeIr₂Ga and YbIr₂Ga. These materials crystallize in the hexagonal Na₃As structure of space group P6₃ cm. Magnetization, specific heat and transport measurements show reduced magnetic moments and the absence of magnetic order above 0.04 K. The quasi-2D structure of these compounds offers the possibility for investigating the role of spatial dimensionality on mixed valence phenomena.     

Ga penetration into polymers

Received: 31 August 1998 / Accepted: 29 October 1998     

Magnetic structure and anisotropy of YFe 6 Ga 6 and HoFe 6 Ga 6

The magnetic structure of RFe₆Ga₆ intermetallic compounds with R = Y, Ho have been determined by neutron powder diffraction, ⁵⁷Fe M?ssbauer spectroscopy, AC susceptibility, TGA (Thermo-Gravimetric Analysis) and magnetization measurements. Both compounds crystallize in the tetragonal ThMn₁₂ structure (space group I4/mmm) with the magnetic structure of YFe₆Ga₆ consisting of a simple ferromagnetic alignment of Fe moments in the basal plane with a Curie temperature of 475(5) K. Gallium atoms are found to fully occupy the 8i site, with Fe and Ga atoms equally distributed over the 8j site, whilst Fe atoms fully occupy the 8f site. The average Fe moments are 1.68(10) and 1.46(10) at 15 and 293 K, respectively. The average room temperature Fe magnetic moments determined by neutron diffraction are in overall agreement with the average Fe moment deduced from M?ssbauer spectroscopy and bulk magnetization measurements on this compound. The magnetic anisotropy of the compound HoFe₆Ga₆ is also planar in the temperature range 6-290 K, with Ho magnetic moments of 9.28(20) and 2.50(20) at 6 K and 290 K, respectively, coupled anti-ferromagnetically to the Fe sublattice and a Curie temperature of 460(10) K. The magneto-crystalline anisotropies of both compounds are comparable at low temperatures. Received 8 March 2001 and Received in final form 18 June 2001     

Surface plasmon enhanced solar-blind photoresponse of Ga2O3film with Ga nanospheres

正Semiconductor solar-blind(220-280 nm)photodetectors(PDs),which have important applications both in civil and military aspects,are mainly based on diamond[1],Al Ga N[2],Mg Zn O[3],and Ga_2O_3[4-11].Among these materials,Ga_2O_3has a direct band gap(~4.9 e V)just falling in solarblind spectral range,which makes Ga_2O_3a desirable candidate for solar-blind photodetection.Up to now,many kinds of Ga_2O_3PDs have been demonstrated including bulk[4,5],film[6-8]and nanostructures[9-11],as summarized in Table 1.From the summary,we can see although bulk GaOdevices     

Transverse excitations in liquid Ga

The transverse acoustic excitation modes were detected by inelastic x-ray scattering in liquid Ga in the Q range above 9?nm^?1 although liquid Ga is mostly described by a hard-sphere liquid. An ab initio molecular dynamics simulation clearly supports this finding. From the detailed analysis for the S(Q,ω) spectra with a good statistic quality, the lifetime of 0.5 ps and the propagating length of 0.4–0.5?nm can be estimated for the transverse acoustic phonon modes, which may correspond the lifetime and size of cages formed instantaneously in liquid Ga. The microscopic Poisson’s ratio estimated from the dynamic velocities of sound is 0.42, indicating a rubber-like soft elastic property of the cages.     

Thermal conductivity of liquid Ga

We present accurate values of the thermal conductivity of liquid Ga calculated from measurements of the Lorenz number and the electrical conductivity.     

Photoconductivity of Ga implanted Si

High resolution spectral photoconductivity measurements are reported for 360 keV, 10¹³ cm⁻² Ga ion implanted Si. The 32 K spectrum shows excited state features and BWF transitions m addition to the impurity-to-band continuum. High resistivity n-type substrates were used without multiple implantation to adjust the compensation. Careful electrical contact to the implanted layers and reverse bias isolation of the shallow implant were necessary to produce the Ga spectra without observing contributions from the substrate.