scholarly journals Advanced Research of the Triassic Clay from the Baltic Region

2012 ◽  
Vol 51 (4) ◽  
pp. 376-382
Author(s):  
J. Karasa ◽  
J. Kostjukovs ◽  
A. Palaša ◽  
A. Actiņš

A procedure of smectite containing clay enrichment has been optimized, and the process of sedimentation has been studied. The new enrichment based method for quantitative determination of clay fraction in smectite containing sediment was developed. A new method for obtaining organoclays from enriched smectite clays has been investigated. The method is based on solid-state reaction between smectite and organic compounds, where organic molecules can be intercalated in dried clay mineral (montmorillonite) by solid-state reactions, without or with use of solvents. The enriched clay and the obtained organoclay samples were characterized with X-ray powder diffraction (PXRD).

1997 ◽  
Vol 52 (9) ◽  
pp. 1031-1036 ◽  
Author(s):  
Nicola Zoche ◽  
Martin Jansen

K3BiO3 and Rb3BiO3 have been synthesized for the first time by solid state reactions of the respective binary compounds. K3BiO3 was obtained from Bi2O3 and K2O at 550 °C, Rb3BiO3 from Bi2O3 and Rb2O at 650 °C. The compounds were structurally examined by single-crystal X -ray investigations (K3BiO3: I 4̅ 3 m, a = 1070.15(2) pm, Z = 8; Rb3BiO3: P 21 3, a = 875.48(2) pm, Z = 4). The structures reveal “isolated” BiO33- groups. While K3BiO3 is isostructural to Na3BiO3, Rb3BiO3 has the same crystal structure as Cs3BiO3.


Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.


1972 ◽  
Vol 9 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Calvert C. Bristol

X-ray powder diffraction methods, successful in quantitative determination of silicate minerals in fine-grained rocks, have been applied to the determination of calcite, dolomite, and magnesite in greenschist facies meta-volcanic rocks. Internal standard graphs employing two standards (NaCl and Mo) have been determined.Carbonate mineral modes (calcite and dolomite) for 6 greenschist facies meta-volcanic rocks obtained by the X-ray powder method have been compared to normative carbonate mineral contents calculated for the same rocks. This comparison showed a maximum variation of 7.7 wt.% between the X-ray modes and the normative carbonate mineral contents of the rocks. Maximum standard deviation for the X-ray modes of these rocks was equivalent to 4.4 wt.%.


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