High-resolution X-ray diffraction and electron microscopy study of porous GaAs substrates

2013 ◽  
Author(s):  
Andrey A. Lomov ◽  
Jan Grym ◽  
Dusan Nohavica ◽  
Andrey S. Orehov ◽  
Alexander L. Vasiliev ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaas Substrates ◽  
Porous Gaas

An Electron Microscopy study of the BaxLa1-xFeO3-x/2 (1/2≤x≤2/3) system

1990 ◽  
Vol 48 (4) ◽  
pp. 608-609
Author(s):  
M. Parras ◽  
J.M. González-Calbet ◽  
M. Vallet-Regí ◽  
J.C. Grenier
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Chemical Analysis ◽  
Analysis Data ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Variations ◽  
Perovskite Unit Cell

In a previous paper we have shown that compositional variations in BaxLa1-xFeO3-y materials prepared in air. are accommodated in a different way than in other perovskite-related ferrites probably due to the bigger size of barium.When oxidated BaxLa1-xFe3+,4+O3-y samples in the 1/2 ≤ x ≤ 2/3 range, are reduced by annealing at 1100°C for 24h. in flowing Ar-5%H2, all iron,as deduced from chemical analysis data, is found in the III state oxidation. Powder X-ray diffraction data in this range (La1/2Ba1/2FeO2.75-La1/3Ba2/3FeO2.67) can be indexed on the basis of a single cubic perovskite unit cell (ac ≃ 3.95Å)In order to elucidate the way in which anionic vacancies are accommodated in these solids an electron diffraction (ED) and microscopy study was performed, similar results being obtained in both La1/2Ba1/2 FeO2.75 and La1/3Ba2/3FeO2.67samples.

High‐resolution electron microscopy study of x‐ray multilayer structures

1987 ◽  
Vol 61 (4) ◽  
pp. 1422-1428 ◽  
Author(s):  
Amanda K. Petford‐Long ◽  
Mary Beth Stearns ◽  
C.‐H. Chang ◽  
S. R. Nutt ◽  
D. G. Stearns ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Multilayer Structures ◽  
X Ray ◽  
Resolution Electron

Single-crystal X-ray diffraction and electron-microscopy study of multiple-twinned Sr3(Ru0.336,Pt0.664)CuO6

2003 ◽  
Vol 59 (2) ◽  
pp. 182-189 ◽  
Author(s):  
Karen Friese ◽  
Lorenz Kienle ◽  
Viola Duppel ◽  
Hongmei Luo ◽  
Chengtian Lin
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Single Crystal ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
X Ray Diffraction ◽  
Threefold Axis ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Twin Model

Sr_3(Ru_{0.336},Pt_{0.664})CuO_6 crystallizes as a monoclinic structure [space group R12/c; lattice parameters a = 9.595 (15), b = 9.595 (15), c = 11.193 (2) Å and \gamma = 120°]. The crystal structure is pseudotrigonal and the crystal investigated here by single-crystal X-ray diffraction was a multiple twin composed of six individuals. The twin laws are a combination of rhombohedral obverse/reverse twinning plus the threefold axis from the trigonal system. The crystal structure is related to the hexagonal perovskites. Each Pt/Ru atom is coordinated pseudo-octahedrally by O atoms, while the overall coordination polyhedra for Cu atoms can be regarded as a strongly distorted trigonal prism, where the Cu atom is clearly shifted from the center. Each [(Ru_{0.336},Pt_{0.664})O_6] octahedron is connected to two Cu—O polyhedra via a common edge, and thus chains are formed parallel to the crystallographic c axis. Sr^{2+} ions are incorporated between the chains and are coordinated by eight O atoms. All bond distances and angles are in good agreement with literature values. Electron-microscopy studies confirm the results from X-ray diffraction and all observed domain structures can be interpreted exactly with the established twin model. No indication of Pt/Ru ordering was found in either the X-ray or the electron-microscopy investigation.

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