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Arsenic Atoms (arsenic + atom)

Distribution by Scientific Domains

Chemistry	75%

Selected Abstracts

Electronic Structure of Binary Phosphoric and Arsenic Triazides

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2006
Zeng Xiaoqing
Abstract Two highly explosive binary triazides of the group 15 elements P(N3)3 and As(N3)3 have been obtained in the gas phase through the heterogeneous reaction of PCl3 and AsCl3, respectively with AgN3 at room temperature. The electronic structures of both triazides have been characterized by photoelectron spectroscopy, combined with quantum chemical calculations. This represents the first electronic study of covalent triazides. The first experimental vertical ionization potentials for P(N3)3 and As(N3)3 are 9.74 and 9.98 eV, with the contribution primarily from the lone pairs of the azido moiety and the arsenic atom, respectively. The results indicate the relative "isolation" of azido moieties in triazides and less stability of these highly explosive compounds in comparison to monoazides and diazides. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

Atomic layer epitaxy of GaMnAs on GaAs(001)

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 4 2007
M. Ozeki
Abstract A self-limiting mechanism in atomic layer epitaxy (ALE) has been investigated for the heterogrowth of GaMnAs on GaAs(001) substrate. In the ALE, trimethylgallium, bismethylcyclopentadienylmanganese and trisdimethylaminoarsine were used as source materials of gallium, manganese and arsenic atoms, respectively. Although the growth of GaMnAs was carried out at a high growth temperature of 500 °C, a distinct self-limiting mechanism was observed for the manganese alloy composition up to 6% and the epitaxial layer had no indications of including MnAs phase. The layer showed an atomically flat surface morphology reflecting the self-limiting growth. The self-limiting mechanism was largely affected by the lattice mismatch between GaMnAs epitaxial layer and GaAs substrate. When the manganese alloy composition exceeded 7%, the self-limiting mechanism was broken and MnAs precipitates were observed in the epitaxial layer. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Incommensurately modulated lanthanide coinage-metal diarsenides.

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2009

Rare-earth metal coinage-metal diarsenides LnTAs2 (Ln = Y, La, Ce,Lu; T = Cu, Ag, Au) are known to crystallize in structures closely related to the HfCuSi2 type, which comprises a stacking sequence of puckered TAs layers and planar square As nets, separated by the Ln atoms. CeAu1,,As2, with , = 0.015,(2), shows an incommensurate positional modulation of the arsenic atoms in the planar As nets. Based on X-ray diffraction data on a twinned crystal, a structure model in the monoclinic superspace group P121/m1(,0,)00 (No. 11.1) with basic unit-cell parameters of a = 5.804,(1), b = 5.814,(1), c = 10.179,(1),Å and , = 90.09,(8)° is presented. The components of the modulation wavevector q = ,a* + 0b* + ,c* are , = 0.08,(1) and , = 0.39,(1). The structure comprises cis,trans chains and rectangles of As atoms and displays an intricate stacking sequence of the modulated arsenic nets. Rod groups and layer groups of the respective arrangements are identified and the arrangement of different motifs of the modulated As net is discussed. [source]

Incommensurately modulated lanthanide coinage-metal diarsenides.

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2009

GdCuAs2, GdAu1,,As2 and TbAu1,,As2 crystallize as incommensurately modulated variants of the HfCuSi2 type. Structure models have been developed in the monoclinic superspace group P121/m1(,0,)00 (No. 11.1). The components of the modulation wavevectors q = ,a* + 0b* + ,c* are , = 0.04,(1) and , = 0.48,(1) for GdCuAs2, , = 0.03,(1) and , = 0.48,(1) for GdAu1,,As2 and , = 0.02,(1) and , = 0.46,(1) for TbAu1,,As2. The predominant effect of the positional modulation is the distortion of a square net of arsenic atoms, which results in planar zigzag chains. Rod groups and layer groups of the respective structure motifs are identified and discussed. [source]