Influence of Free Charge on the Lattice Parameters of GaN and Other Semiconductors

1997 ◽  
Vol 468 ◽  
Author(s):  
M. Leszczyński ◽  
J. Bąk-Misiuk ◽  
J. Domagała ◽  
T. Suski
Keyword(s):  
Lattice Parameters ◽  
Deformation Potential ◽  
Free Charge ◽  
Bulk Crystals ◽  
Free Electrons ◽  
X Ray ◽  
Mg Doping ◽  
Conduction Bands ◽  
Vegard’S Law ◽  
Homoepitaxial Layers

ABSTRACTLattice parameters of semiconductors depend on the concentration of free electrons via the deformation potentials of the occupied minima of the conduction bands. In the presented work we examined the lattice parameters of variously doped GaN samples (epitaxial layers on sapphire and on SiC, bulk crystals grown at high hydrostatic pressure and homoepitaxial layers). The following dopants were used: Si, Mg and O. The measurements were performed using high resolution X-ray diffractometry. The results indicate that free electrons expand the lattice what confirms a negative value of the deformation potential of the Γ minimum of the conduction band. However, for Mg-doping (acceptor) we observed the lattice expansion as well. This violates the Vegard's law, as Mg ions are smaller than Ga ions.

Effects of lithium, indium, and zinc on the lattice parameters of magnesium

2008 ◽  
Vol 23 (12) ◽  
pp. 3379-3386 ◽  
Author(s):  
A. Becerra ◽  
M. Pekguleryuz
Keyword(s):  
Solid Solution ◽  
Brillouin Zone ◽  
Electron Concentration ◽  
Axial Ratio ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vegard’S Law

The lattice parameters of magnesium solid-solution alloys with lithium, indium, and/or zinc have been determined via x-ray diffraction (XRD). Li decreased the axial ratio (c/a) of Mg from 1.624 to 1.6068 within 0–16 at.% Li. Indium increased the c/a of Mg to 1.6261 with increasing In toward 3.3 at.% while Zn showed no effect on c/a in the 0.2–0.7 at.% range. The effects were explained by electron overlap through the first Brillouin zone and by Vegard’s Law. A relationship was determined between electron concentration (e/a) and c/a as c/a = −15.6(e/a)2 + 60(e/a) − 55.8.

Synthesis and Investigation of the Structural Properties of Al3+ Doped Mg Ferrites

2015 ◽  
Vol 789-790 ◽  
pp. 48-52 ◽  
Author(s):  
Shahzad Hossain ◽  
Mohammad Kamrul Hasan ◽  
S.K. Md. Yunus ◽  
A.K.M. Zakaria ◽  
Tapash Kumar Datta ◽  
...  
Keyword(s):  
Bulk Density ◽  
Rietveld Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Cubic Symmetry ◽  
X Ray ◽  
Al Content ◽  
Vegard’S Law ◽  
Ray Density ◽  
State Ceramic

The polycrystalline ferrites of MgAlxFe2-xO4 (0.0≤x≤0.4) were prepared by the conventional solid state ceramic method. The specimens were sintered at 13500C and X-ray diffraction experiments were done at room temperature which showed single phased cubic spinel structure. The lattice parameters were determined from the XRD data using Nelson-Riley extrapolation method and found to decrease with increasing Al concentration obeying Vegard’s law. The cation distribution and oxygen position parameters have also been determined by refining the data using the RIETAN-2000 in the Rietveld method which reveals that the samples possess cubic symmetry corresponding to the space group Fd-3m. The X-ray density and bulk density of each sample were calculated using the lattice parameters. The porosity has been determined from X-ray density (ρx) and bulk density (ρB) and it changes monotonically with Al content.

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Binary Compound ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

scholarly journals Effects of Thermal Annealing on the Properties of Zirconium-Doped MgxZn1−XO Films Obtained through Radio-Frequency Magnetron Sputtering

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 373
Author(s):  
Wen-Yen Lin ◽  
Feng-Tsun Chien ◽  
Hsien-Chin Chiu ◽  
Jinn-Kong Sheu ◽  
Kuang-Po Hsueh
Keyword(s):  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Photoelectron Spectroscopy ◽  
Annealing Temperature ◽  
Radio Frequency Magnetron ◽  
Radio Frequency Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Free Electrons ◽  
X Ray ◽  
Mg Content

Zirconium-doped MgxZn1−xO (Zr-doped MZO) mixed-oxide films were investigated, and the temperature sensitivity of their electric and optical properties was characterized. Zr-doped MZO films were deposited through radio-frequency magnetron sputtering using a 4-inch ZnO/MgO/ZrO2 (75/20/5 wt%) target. Hall measurement, X-ray diffraction (XRD), transmittance, and X-ray photoelectron spectroscopy (XPS) data were obtained. The lowest sheet resistance, highest mobility, and highest concentration were 1.30 × 103 Ω/sq, 4.46 cm2/Vs, and 7.28 × 1019 cm−3, respectively. The XRD spectra of the as-grown and annealed Zr-doped MZO films contained MgxZn1−xO(002) and ZrO2(200) coupled with Mg(OH)2(101) at 34.49°, 34.88°, and 38.017°, respectively. The intensity of the XRD peak near 34.88° decreased with temperature because the films that segregated Zr4+ from ZrO2(200) increased. The absorption edges of the films were at approximately 348 nm under 80% transmittance because of the Mg content. XPS revealed that the amount of Zr4+ increased with the annealing temperature. Zr is a potentially promising double donor, providing up to two extra free electrons per ion when used in place of Zn2+.

scholarly journals β-Y(BO2)3 – a new member of the β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu) structure family

2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).

Extended X-ray Absorption Fine Structure Studies of InGaN Epilayers

2004 ◽  
Vol 831 ◽  
Author(s):  
V. Katchkanov ◽  
K.P. O'Donnell ◽  
J.F.W. Mosselmans ◽  
S. Hernandez ◽  
R.W. Martin ◽  
...  
Keyword(s):  
Fine Structure ◽  
Bond Length ◽  
Molar Fraction ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
X Ray ◽  
Absorption Fine ◽  
Vegard’S Law ◽  
Metal Organic ◽  
X Ray Absorption

ABSTRACTThe local structure around In atoms in InGaN epilayers grown by Molecular Beam Epitaxy (MBE) and by Metal-Organic Chemical Vapour Deposition (MOCVD) was studied by means of Extended X-ray Absorption Fine Structure (EXAFS). The averaged In fraction of MOCVD grown samples ranged from 10% to 40% as estimated by Electron Probe Microanalysis (EPMA). The In fraction of MBE grown samples spanned the range from 13% to 96%. The In–N bond length was found to vary slightly with composition, both for MBE and MOCVD grown samples. Moreover, for the same In content, the In-N bond lengths in MOCVD samples were longer than those in MBE grown samples. In contrast, the In-In radial separations in MOCVD and MBE samples were found to be indistinguishable for the same In molar fraction. The In-Ga bond length was observed to deviate from average cation-cation distance predicted by Vegard's law for MBE grown samples which indicates alloy compositional fluctuations.

Notizen: Synthesis and Crystal Data of the Bismuth Sulphide Chloride B19Si27Cl3

1974 ◽  
Vol 29 (9-10) ◽  
pp. 688-689 ◽  
Author(s):  
Volker Krämer
Keyword(s):  
Title Compound ◽  
Hexagonal Lattice ◽  
Lattice Parameters ◽  
Crystal Data ◽  
X Ray ◽  
Space Groups ◽  
Sinter Technique

The title compound was synthesized by a sinter technique at 560°C. X ray powder data are listed, the hexagonal lattice parameters are a = 15.403 (3) and c = 4.015 (2) Å; possible space groups are P63 and P63/m.

Superstructure formation in the solid solution Sc3Pt3−xIn3 (x = 0–0.93)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nataliya L. Gulay ◽  
Rolf-Dieter Hoffmann ◽  
Jutta Kösters ◽  
Yaroslav M. Kalychak ◽  
Stefan Seidel ◽  
...  
Keyword(s):  
Solid Solution ◽  
Diffraction Data ◽  
High Frequency ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Platinum Content ◽  
Arc Melting ◽  
Modulation Vector

Abstract The equiatomic indide ScPtIn (ZrNiAl type, space group P 6 ‾ $‾{6}$ 2m) shows an extended solid solution Sc3Pt3–xIn3. Several samples of the Sc3Pt3–xIn3 series were synthesized from the elements by arc-melting and subsequent annealing, or directly in a high frequency furnace. The lowest platinum content was observed for Sc3Pt2.072(3)In3. All samples were characterized by powder X-ray diffraction and their lattice parameters and several single crystals were studied on the basis of precise single crystal X-ray diffractometer data. The correct platinum occupancy parameters were refined from the diffraction data. Decreasing platinum content leads to decreasing a and c lattice parameters. Satellite reflections were observed for the Sc3Pt3–xIn3 crystals with x = 0.31–0.83. These satellite reflections could be described with a modulation vector ( 1 3 , 1 3 , γ ) $\left(\frac{1}{3},\frac{1}{3},\gamma \right)$ ( γ = 1 2 $\gamma =\frac{1}{2}$ c* for all crystals) and are compatible with trigonal symmetry. The interplay of platinum filled vs. empty In6 trigonal prisms is discussed for an approximant structure with space group P3m1.

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