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Related papers: Stabilization of amorphous GaN by oxygen

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While crystalline two-dimensional materials have become an experimental reality during the past few years, an amorphous 2-D material has not been reported before. Here, using electron irradiation we create an sp2-hybridized one-atom-thick…

Materials Science · Physics 2011-03-22 J. Kotakoski , A. V. Krasheninnikov , U. Kaiser , J. C. Meyer

We report on an inelastic (Raman) light scattering study of the local structure of amorphous GeTe films. A detailed analysis of the temperature-reduced Raman spectra has shown that appreciable structural changes occur as a function of…

Materials Science · Physics 2009-11-11 K. S. Andrikopoulos , S. N. Yannopoulos , G. A. Voyiatzis , A. V. Kolobov , M. Ribes , J. Tominaga

We present spatially resolved gas kinematics, ionization, and energetics of 11 type 1 and 5 type 2 active galactic nuclei (AGNs) with strong ionized gas outflows at z $<0.3$ using Gemini Multi-Object Spectrograph Integral Field Unit…

Astrophysics of Galaxies · Physics 2023-10-13 Changseok Kim , Jong-Hak Woo , Rongxin Luo , Aeree Chung , Junhyun Baek , Huynh Anh N. Le , Donghoon Son

Both hexagonal wurtzite and cubic zinc blend GaN phases were synthesized in GaAs by 50 keV N+ implantation at 400 deg C and subsequent annealing at 900 deg C for 15 min in N2 ambient. Crystallographic structural and Raman scattering studies…

We study the growth of the Fe films on GaAs(100) at a low temperature, 140 K, by $in$-$situ$ UHV x-ray reflectivity using synchrotron radiation. We find rough surface with the growth exponent, $\beta_S$ = 0.51$\pm$0.04. This indicates that…

Materials Science · Physics 2007-05-23 T. C. Kim , J. -M. Lee , Y. Kim , D. Y. Noh , S. -J. OH , J. -S. Kim

The reionization of hydrogen in the intergalactic medium (IGM) is a crucial landmark in the history of the universe, but the processes through which it occurs remain mysterious. In particular, recent numerical and analytic work suggest that…

Astrophysics · Physics 2009-11-10 Steven Furlanetto , Lars Hernquist , Matias Zaldarriaga

There is increasing evidence that the highly ionized multiphase components of AGN disk winds may be due to thermal instability. The ions responsible for forming the observed X-ray absorption lines may only exist in relatively cold clumps…

Astrophysics of Galaxies · Physics 2017-02-08 Tim Waters , Daniel Proga , Randall Dannen , Tim Kallman

We study the formation of a partially ionized zone behind the usual H II zone in photo-ionized gas for gas density intermediate between ordinary H II regions and AGN BLRs and without X-rays. While Lyman continuum photons are depleted before…

Astrophysics of Galaxies · Physics 2025-04-02 Liang Dai

The hot-wall metal-organic chemical vapor deposition (MOCVD), previously shown to enable superior III-nitride material quality and high performance devices, has been explored for Mg doping of GaN. We have investigated the Mg incorporation…

Cracking of thick GaN films on sapphire substrates during the cooling down after the growth was studied. The cracking was suppressed by increasing the film-to-substrate thickness ratio and by using an intermediate carbon buffer layer, that…

Materials Science · Physics 2019-03-06 Vladislav Voronenkov , Andrey Leonidov , Yuri Lelikov , Andrey Zubrilov , Yuri Shreter

We explore various instability models for the onset of star formation in irregular galaxies. Critical gas densities are calculated for gravitational instabilities with a thin, pure-gas disk, and with a thick disk composed of gas and a…

Astrophysics · Physics 2009-10-30 Deidre A. Hunter , Bruce G. Elmegreen , Aomawa L. Baker

We present a systematic study of ionized gas outflows based on the velocity shift and dispersion of the [O III] {\lambda}5007 $\AA$ emission line, using a sample of ~ 5000 Type 1 AGNs at z < 0.3 selected from Sloan Digital Sky Survey. This…

Astrophysics of Galaxies · Physics 2018-09-26 Suvendu Rakshit , Jong-Hak Woo

Anomalous Hall crystals (AHCs) are exotic phases of matter that simultaneously break continuous translation symmetry and exhibit the quantum anomalous Hall effect. AHCs have recently been proposed to explain the observation of an integer…

Strongly Correlated Electrons · Physics 2026-04-28 Félix Desrochers , Mark R. Hirsbrunner , Joe Huxford , Adarsh S. Patri , T. Senthil , Yong Baek Kim

We have investigated recrystallization of amorphous Yttrium Iron Garnet (YIG) by annealing in oxygen atmosphere. Our findings show that well below the melting temperature the material transforms into a fully epitaxial layer with exceptional…

Materials Science · Physics 2015-06-15 C. Hauser , T. Richter , N. Homonnay , C. Eisenschmidt , H. Deniz , D. Hesse , S. Ebbinghaus , G. Schmidt

GaN films with thicknesses up to 3 mm were grown in two custom-made halide vapor phase epitaxy (HVPE) reactors. V-shaped defects (pits) with densities from 1 cm$^{-2}$ to 100 cm$^{-2}$ were found on the surfaces of the films. Origins of pit…

By mixing glass beads with a curable polymer we create a well-defined cohesive granular medium, held together by solidified, and hence elastic, capillary bridges. This material has a geometry similar to a wet packing of beads, but with an…

Soft Condensed Matter · Physics 2016-11-16 Arnaud Hemmerle , Matthias Schröter , Lucas Goehring

Using a sample of 24264 optically selected AGNs from the SDSS DR7 database, we characterise how the profile of the [OIII] emission line relates to bolometric luminosity (L_Bol), Eddington ratio, radio loudness, radio luminosity (L_Rad) and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 J. R. Mullaney , D. M. Alexander , S. Fine , A. D. Goulding , C. M. Harrison , R. C. Hickox

Graphene/AlGaN/GaN heterostructures are proposed to investigate the drag and two-stream instability effects. In this study, graphene grown by chemical vapor deposition was transferred from copper onto the top of the standard AlGaN/GaN…

Mesoscale and Nanoscale Physics · Physics 2026-01-27 A. Rehman , D. B. But , P. Sai , M. Dub , P. Prystawko , A. Krajewska , G. Cywinski , W. Knap , S. Rumyantsev

GaN based high electron mobility transistors show promise in numerous device applications which elicits the need for accurate models of bulk, surface, and interface electronic properties. We detail here a hybrid density functional theory…

Materials Science · Physics 2021-10-20 Eric Welch , Luisa Scolfaro

We report the results of a detailed study of the structural, magnetic and magnetotransport properties of as-grown and annealed Ga0.91Mn0.09As thin films grown on (311)A and (311)B GaAs substrates. The high Curie temperature and hole density…

Materials Science · Physics 2009-11-11 K. Y. Wang , K. W. Edmonds , L. X. Zhao , M. Sawicki , R. P. Campion , B. L. Gallagher , C. T. Foxon