Effect of ion‐beam damage on x‐ray diffraction and Raman spectra of amorphous GeSe2

1983 ◽  
Vol 54 (4) ◽  
pp. 1792-1794 ◽  
Author(s):  
M. Marcus ◽  
R. C. Dynes ◽  
J. E. Griffiths ◽  
D. McWhan
Keyword(s):  
Raman Spectra ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Beam Damage

Tetragonal Strain in MBE GexSi1-x Films Grown on (100) Si Observed by Ion Channeling and X-Ray Diffraction

1983 ◽  
Vol 25 ◽  
Author(s):  
A. T. Fiory ◽  
L. C. Feldman ◽  
J. C. Bean ◽  
I. K. Robinson
Keyword(s):  
Molecular Beam ◽  
Critical Thickness ◽  
Ion Beam ◽  
Growth Surface ◽  
X Ray Diffraction ◽  
Strained Layers ◽  
X Ray ◽  
Ion Channeling ◽  
Pseudomorphic Growth ◽  
Beam Damage

ABSTRACTStructure of GexSi1-x alloy films grown on (100) Si by molecular beam epitaxy is analyzed by MeV He+ ion channeling and X-ray diffraction as functions of Ge concentration, film thickness and growth temperature. Critical thicknesses for pseudomorphic growth are determined for x ≤ 0.5, where coherent tetragonally-strained layers are observed. The average strain decreases approximately as the square-root of thickness when the critical thickness is exceeded. At temperatures near the threshold for islanding growth, surface roughness appears as a precursor to degradation of strained-layer epitaxy. No effect on the amount of the tetragonal strain was found in a study of ion-beam damage.

Ion Beam Synthesis and Optical Properties of Zn and Zno Nanocrystals in Sio2 and Caf2 Substrates

2003 ◽  
Vol 777 ◽  
Author(s):  
Y.C. Liu ◽  
R. Mu ◽  
H.Y. Xu ◽  
Y.M. Lu ◽  
D.Z. Shen ◽  
...  
Keyword(s):  
Ion Beam ◽  
Green Emission ◽  
Zinc Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reducing Atmosphere ◽  
Zno Nanocrystals ◽  
Nanocrystal Formation ◽  
Beam Damage ◽  
Zno Nanocrystal

AbstractIon implantation was used to inject zinc ions into crystalline CaF2 and amorphous SiO2 substrates. Zn or ZnO nanoparticles were formed after annealing in a reducing (4% H2 + 96%Ar) or an oxidizing (10%O2 + 90% Ar ) atmosphere, respectively. When the sample was annealed in a reducing atmosphere, the absorption band at ∼ 5.3 eV for zinc implanted into SiO2 was attributed to zinc metal colloids. The absorption peak observed in the 4.3 – 4.7 eV region was due to the formation of ZnO nanocrystals, after the sample was annealed in an oxidizing environment. Both X-ray diffraction (XRD) and X-ray photospectroscopy (XPS) were used to confirm ZnO nanocrystal formation. For zinc implanted into CaF2, the as-formed ZnO nanocrystals were aligned with their [002] axes parallel to the [111] axis of the CaF2. Photoluminescence (PL) spectra showed UV and green emission from the zinc-implanted silica samples annealed under an oxygen atmosphere; however, no green emission was observed for ZnO formed in a CaF2 substrate. An additional emission was observed at ∼ 420 nm which might be due to F centers in CaF2 created by ion beam damage.

Mev Ion Beam Synthesis of Well-Defined Buried 3C-Sic Layers in Silicon

1995 ◽  
Vol 396 ◽  
Author(s):  
J.K.N. Lindner ◽  
B. Götz ◽  
A. Frohnwieser ◽  
B. Stritzker
Keyword(s):  
Electron Diffraction ◽  
Depth Distribution ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ion Beam Synthesis ◽  
Post Implantation

AbstractWell-defined, homogenous, deep-buried 3C-SiC layers have been formed in silicon by ion beam synthesis using MeV C+ ions. Layers are characterized by RBS/channeling, X-ray diffraction, x-sectional TEM and electron diffraction. The redistribution of implanted carbon atoms into a rectangular carbon depth distribution associated with a well-defined layer during the post-implantation anneal is shown to depend strongly on the existence of crystalline carbide precipitates in the as-implanted state.

Characterization of Natural and Synthesized FeTiO3 Crystals With RBS/PIXE/XRD

1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  
Keyword(s):  
Single Crystals ◽  
Ion Beam ◽  
Pressure Control ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Beam Analysis ◽  
Ppm Level

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.

Formation and Thermal Stability of Nd0.32Y0.68Si1.7 Layers Formed by Channeled Ion Beam Synthesis

1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Beam ◽  
Hexagonal Structure ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Ion Beam Synthesis ◽  
Thermal Stability Of

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

scholarly journals Synthesis and Structural Properties of Nanocomposites Based on Synthetic Opals and Active Dielectrics

2019 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Bilal Abu Sal
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystals ◽  
Structural Properties ◽  
Raman Spectra ◽  
Phase Structure ◽  
Opal Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal State ◽  
Synthetic Opals

This work is devoted to generalize and analyze the previouse results of new photonic-crystalline nanomaterials based on synthetic opals and active dielectrics. Data were characterized by X-ray diffraction and Raman spectroscopy. Active dielectrics infiltrated into the pores of the opal from the melt. The phase structure composition of the infiltrated materials into the pores of the opal matrix were analyzed. The results of x-ray diffraction and Raman spectra allowed to establish the crystal state of active dielectrics in the pores of the opal. The Raman spectra of some opal-active dielectric nanocomposites revealed new bands and changes in band intensities compared to the spectra of single crystals of active dielectrics. Further more, differences in band intensities in the spectra were measured at different spots of the sample‘s surface were observed. The revealed changes were attributed to the formation of new crystalline phases due to the injected dielectrics in opal pores.

Changes in the Spectral Characteristics of Aluminum Films Deposited under Assisting Argon Ion Beam

2015 ◽  
Vol 1084 ◽  
pp. 11-15
Author(s):  
Sergey P. Umnov ◽  
Oleg Kh. Asainov ◽  
Svetlana N. Popova ◽  
Aleksey N. Lemachko
Keyword(s):  
Magnetron Sputtering ◽  
Ion Beam ◽  
Spectral Characteristics ◽  
Crystal Defects ◽  
X Ray Diffraction ◽  
Aluminum Films ◽  
X Ray ◽  
Ion Assistance ◽  
Argon Ion ◽  
Uv Range

High-reflectance aluminum films are widely used in applied optics. As part of this work, we deposited aluminum films on glass substrates by magnetron sputtering using argon ion beam assistance. The reflectivity of the films obtained was measured on the SF-256 spectrophotometer. The microstructure and topology of the films were examined with a transmission electron microscope (TEM), X-ray diffraction (XRD) and atomic force microscope (AFM). The studies have shown that the aluminum films deposited with ion assistance have higher reflectance in the UV range than the films formed by magnetron sputtering alone. The results of TEM and AFM measurements show that the geometric factor (crystallite size, surface roughness) is not the reason for the increase of reflectivity. X-ray diffraction analyses have shown a significant increase in microstress in the aluminum films deposited with ion assistance, which is caused by an increase in the defect density of the vacancy-type crystal structure. The results have shown that the increase in the density of crystal defects leads to an increase in reflectance in the UV range.

Crystal chemistry of lamprophyllite-group minerals from the Murun alkaline complex (Russia) and pegmatites of Rocky Boy and Gordon Butte (USA): single crystal X-ray diffraction and Raman spectroscopy study

2021 ◽  
Vol 77 (2) ◽  
Author(s):  
Sergey M. Aksenov ◽  
Anastasia D. Ryanskaya ◽  
Yuliya V. Shchapova ◽  
Nikita V. Chukanov ◽  
Nikolay V. Vladykin ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Raman Spectra ◽  
Crystal Chemistry ◽  
Solid Solution Series ◽  
X Ray Diffraction ◽  
Alkaline Complex ◽  
Oh Groups ◽  
X Ray ◽  
Solution Series

Specific features of the crystal chemistry of lamprophyllite-group minerals (LGMs) are discussed using the available literature data and the results of the single-crystal X-ray diffraction and a Raman spectroscopic studies of several samples taken from the Murun alkaline complex (Russia), and Rocky Boy and Gordon Butte pegmatites (USA) presented here. The studied samples are unique in their chemical features and the distribution of cations over structural sites. In particular, the sample from the Gordon Butte pegmatite is a member of the barytolamprophyllite–emmerichite solid solution series, whereas the samples from the Murun alkaline complex and from the Rocky Boy pegmatite are intermediate members of the solid solution series formed by lamprophyllite and a hypothetical Sr analogue of emmerichite. The predominance of O2− over OH− and F− at the X site is a specific feature of sample Cha-192 from the Murun alkaline complex. New data on the Raman spectra of LGMs obtained in this work show that the wavenumbers of the O—H stretching vibrations depend on the occupancies of the M2 and M3 sites coordinating with (OH)− groups. Cations other than Na+ and Ti4+ (mainly, Mg and Fe3+) can play a significant role in the coordination of the X site occupied by (OH)−. Data on polarized Raman spectra of an oriented sample indicate that the OH groups having different local coordinations have similar orientations with respect to the crystal. The calculated measures of similarity (Δ) for lamprophyllite and ericssonite are identical (0.157 and 0.077 for the 2M- and 2O-polytypes, respectively), which indicates that these minerals are crystal-chemically isotypic and probably should be considered within the same mineral group by analogy to the other mineralogical groups which combine isotypic minerals.

Detection of Phase Purity of Sr2FeMoO6 by Raman Spectroscopy

2014 ◽  
Vol 989-994 ◽  
pp. 130-133
Author(s):  
Zhen Feng Xu ◽  
Qin Zhang ◽  
Suo Jia Yuan
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Broad Peak ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray

. The micro-Raman technique is used to examine the phase purity of Sr2FeMoO6 compound in this work. It is found that the Raman spectra of Sr2FeMoO6 compound without impurity consists of the peaks at about 440cm-1 and 620cm-1. The broad peak and shoulder at 820-890cm-1 in the Raman spectra is assigned to the most common impurity SrMoO4 and some other unidentified co-existing phases, which is approved by the results of X-ray diffraction.

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