Mechanism of fe impurity incorporation into semi-insulating gaas crystals

ABSTRACTThe growth of high quality ZnSe by organometallic vapor phase epitaxy (OMVPE) has generally been hindered because of parasitic source pre-reactions or relatively high source decomposition temperatures. In this work, we have used vacuum ultraviolet photons generated by a disk-plasma lamp to assist the ZnSe growth process using diethylselenium and diethylzinc as source materials. This approach has resulted in satisfactory growth rates and high material quality at temperatures as low as 250°C, without the limitations of prereaction typically observed when H2Se is used for the selenium source material. In addition, the alkyl selenium compound offers advantages due to reduced toxicity compared to H2Se. This new, low-growth-temperature process thus offers the possibility of improved stoichiometry and impurity incorporation control as well as a reduced thermal effect on the underlying substrate during growth. At the same time, the advantages of excellent morphology and uniformity typically exhibited by the alkylbased growth processes are retained.

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First principles investigation on the electronic structure and magnetism of dilute Fe impurity in PdHx (0⩽x⩽1.0) alloys

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2018.06.017 ◽

2018 ◽

Vol 466 ◽

pp. 17-21

Author(s):

S.N. Mishra

Keyword(s):

Electronic Structure ◽

First Principles ◽

Fe Impurity

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О возможности введения примеси железа в узлы A в SrTiO-=SUB=-3-=/SUB=-

Физика твердого тела ◽

10.21883/ftt.2022.03.52095.242 ◽

2022 ◽

Vol 64 (3) ◽

pp. 345

Author(s):

И.А. Случинская ◽

А.И. Лебедев

Keyword(s):

Annealing Temperature ◽

Local Environment ◽

First Principles Calculations ◽

X Ray Diffraction ◽

Xafs Spectroscopy ◽

Deviation From Stoichiometry ◽

High Annealing ◽

A Site ◽

Fe Impurity ◽

Exafs Spectra

The local environment and oxidation state of the Fe impurity in strontium titanate are studied using XAFS spectroscopy. The influence of annealing temperature and deviation from stoichiometry on the possibility of incorporation of the impurity into the A and B sites of the perovskite structure is studied. The results obtained from the X-ray diffraction, XANES spectra, and EXAFS spectra suggest that at high annealing temperature the iron atoms, at least partially (up to 30%), enter the A sites in SrTiO3. The obtained results agree with results of first-principles calculations, according to which the iron at the A site exhibits strong off-centering (the displacement of ~1 Angstrom), similar to that previously established in SrTiO3 samples doped with Mn and Co.

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Fe Impurity Effects on the Transport Properties in a-(La70Cu30)100−xFex*

Zeitschrift für Physikalische Chemie ◽

10.1524/zpch.1988.157.part_2.789 ◽

1988 ◽

Vol 157 (Part_2) ◽

pp. 789-795

Author(s):

L. Gonzo ◽

G. Fritsch ◽

E. Lüscher

Keyword(s):

Transport Properties ◽

Impurity Effects ◽

Fe Impurity

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ZnO MOVPE growth: From local impurity incorporation towards p-type doping

Superlattices and Microstructures ◽

10.1016/j.spmi.2005.08.010 ◽

2005 ◽

Vol 38 (4-6) ◽

pp. 245-255 ◽

Cited By ~ 25

Author(s):

A. Dadgar ◽

A. Krtschil ◽

F. Bertram ◽

S. Giemsch ◽

T. Hempel ◽

...

Keyword(s):

Impurity Incorporation ◽

Movpe Growth ◽

P Type

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Influence of Impurities on the High-Temperature Water-Vapour Corrosion of Environmental Barrier Rare-Earth Silicates

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1780 ◽

2007 ◽

Vol 336-338 ◽

pp. 1780-1783 ◽

Cited By ~ 2

Author(s):

N. Maier ◽

K.G. Nickel ◽

Georg Rixecker

Keyword(s):

Rare Earth ◽

Surface Phase ◽

Impurity Incorporation ◽

Corrosion Rates ◽

High Temperature Water ◽

Profound Influence ◽

Liquid Phases ◽

Saturation Effects ◽

Influence Of Impurities ◽

Temperature Water

Corrosion experiments on a number of rare earth di-silicates containing Y, Yb and Lu have been conducted in flowing air with 30 vol.% H2O at 1500°C. Nominally the corrosion rate is slower by a factor 5 to 10 compared to silica. However, alumina impurity incorporation has a profound influence on the process of corrosion as it masks not only the gravimetric results but also changes the surface phase assemblages to contain rare earth garnets and liquid phases. It is presumed that silica loss occurs under those conditions via the liquid phase and does not necessarily follow the same kinetics as direct silicate corrosion. Furthermore, atmospheric silicon hydroxide saturation effects contribute to the corrosion process. Currently all determined corrosion rates of rare earth silicates are viewed as system specific only.

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