Investigation of crystal lattice defects of PbZrO3 single crystals by transmission electron microscopy

1980 ◽  
Vol 15 (11) ◽  
pp. 1317-1321 ◽  
Author(s):  
A. A. Dobrikov ◽  
O. V. Presnyakova
1980 ◽  
Vol 15 (2) ◽  
pp. 207-212 ◽  
Author(s):  
A. A. Dobrikov ◽  
O. V. Presnyakova ◽  
V. I. Zaitsev ◽  
V. V. Prisedskii ◽  
G. F. Pan'ko

Author(s):  
J.G. Wen ◽  
K.K. Fung

Bi-based superconducting phases have been found to be members of a structural series represented by Bi2Sr2Can−1Cun−1On+4, n=1,2,3, and are referred to as 2201, 2212, 2223 phases. All these phases are incommensurate modulated structures. The super space groups are P2/b, NBbmb 2201, 2212 phases respectively. Pb-doped ceramic samples and single crystals and Y-doped single crystals have been studied by transmission electron microscopy.Modulated structures of all Bi-based superconducting phases are in b-c plane, therefore, it is the best way to determine modulated structure and c parameter in diffraction pattern. FIG. 1,2,3 show diffraction patterns of three kinds of modulations in Pb-doped ceramic samples. Energy dispersive X-ray analysis (EDAX) confirms the presence of Pb in the three modulated structures. Parameters c are 3 0.06, 38.29, 30.24Å, ie 2212, 2223, 2212 phases for FIG. 1,2,3 respectively. Their average space groups are all Bbmb.


1994 ◽  
Vol 70 (5) ◽  
pp. 1077-1094 ◽  
Author(s):  
J. J. Couderc ◽  
S. Fritsch ◽  
M. Brieu ◽  
G. Vanderschaeve ◽  
M. Fagot ◽  
...  

Author(s):  
K. Seshan ◽  
H.-R. Wenk

Asbestos fibre texture occurs in various mineral groups (e.g. chrysotile, crocidolite, tremolite, grunerite, tourmaline) and it has been established that at least chrysotile is carcinogenic. We are investigating various aspects of the asbestos structure, with transmission electron microscopy (TEM) (1) in order to develop methods for unequivocal asbestos identification using minute samples and also to determine defects responsible for the fibre structure in these minerals which often occur as large, we 11-developed single crystals.In order to do this, we have started by investigating clinoamphibole asbestos such as tremolite Ca2Mg5[Si8O22] (OH, F)2 and crocidolite Na2 (Mg, Al, Fe3+, Fe2+) (Si8O22) (OH, F )2 , from California localities. In crocidoli te - asbestos we observed a high density of very narrow microtwins parallel to the fibre axis [001] (Fig. 1). They are often only 50-100Å wide. Diffraction patterns display the typical twin arrangement of spots and although preliminary contrast experiments are not yet conclusive the twin plane appears to be (100).


2009 ◽  
Vol 64 (8) ◽  
pp. 922-928 ◽  
Author(s):  
Manuel Christian Schaloske ◽  
Hansjürgen Mattausch ◽  
Viola Duppel ◽  
Lorenz Kienle ◽  
Arndt Simon

The compounds Pr6(C2)Br10, Pr10(C2)2Br15 and Pr14(C2)3Br20 were prepared from PrBr3 and the appropriate amounts of Pr and C and characterized by X-ray structure analyses of single crystals. All three compounds crystallize in space group P1 with lattice parameters a = 7.571(2), b = 9.004(2), c = 9.062(2) Å ,α = 108.57(3), β = 97.77(3), γ = 106.28(3)◦ for Pr6(C2)Br10; a = 9.098(2), b = 10.127(2), c = 10.965(2) A° , α = 70.38(3), β = 66.31(3), γ = 70.84(3)◦ for Pr10(C2)2Br15; a = 9.054(2), b = 10.935(2), c = 13.352(3) Å , α = 86.27(3), β = 72.57(3), γ = 66.88(3)◦ for Pr14(C2)3Br20. They are members of a general series Ln4n+2(C2)nBr5n+5 and isostructural with the corresponding iodides known for Ln = La, Ce, Pr. Pr6(C2)Br10 was further characterized via transmission electron microscopy techniques


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