scholarly journals X-ray and neutron diffraction investigations of the structural phase transformation sequence under electric field in 0.7Pb(Mg1∕3Nb2∕3)-0.3PbTiO3 crystal

2004 ◽  
Vol 96 (3) ◽  
pp. 1620-1627 ◽  
Author(s):  
Feiming Bai ◽  
Naigang Wang ◽  
Jiefang Li ◽  
D. Viehland ◽  
P. M. Gehring ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Neutron Diffraction ◽  
Electric Field ◽  
Structural Phase ◽  
Structural Phase Transformation ◽  
X Ray ◽  
Transformation Sequence

Powder X-ray diffraction and Rietveld analysis of La1−xBaxCoO3 (0

2006 ◽  
Vol 21 (4) ◽  
pp. 304-306 ◽  
Author(s):  
Wanju Luo ◽  
Fangwei Wang
Keyword(s):  
Phase Transformation ◽  
Bond Length ◽  
Structural Properties ◽  
Powder Diffraction ◽  
Bond Angle ◽  
Structural Phase ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
Structural Phase Transformation ◽  
X Ray

Detailed structural properties of La1−xBaxCoO3 (LBCO) have been investigated by means of X-ray powder diffraction and Rietveld analysis. A structural phase transformation from R3c to Pm3m at x=0.30–0.35 has been detected based on a comparison between the refinements of R3c and Pm3m. The Co–O bond length of the CoO6 octahedron expanded rapidly with increasing Ba content when x<0.1, and then it leveled off and kept constant at 0.1⩽x⩾0.35, where the Co–O–Co bond angle reaches 180°. The Co–O bond length expansion resumed with increasing Ba content beyond x=0.35.

Determination of Residual Stresses in Transformation-Toughened Ceramics

1983 ◽  
Vol 27 ◽  
pp. 221-228
Author(s):  
M. R. James ◽  
D. J. Green ◽  
F. F. Lange
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Ion Exchange ◽  
Structural Phase ◽  
Surface Chemical ◽  
Structural Phase Transformation ◽  
Surface Residual Stress ◽  
X Ray ◽  
Surface Chemical Reactions

The strength of ceramics or glasses can be increased by placing their surfaces into compression. Techniques include ion exchange, temperature glazing, surface chemical reactions and stress-induced phase transformations. Although most of these techniques are well recognized, little effort has been expended In experimentally determining the magnitude of the compressive stress, and in particular, to use experimental evidence to identify important material and process parameters that need to be controlled. The goal of this investigation was to determine some of the factors that effect the magnitude, profile and depth of the compressive layer introduced by a structural phase transformation. X-ray residual stress measurements were used to directly determine the state of the surface residual stress.

Powder X-ray diffraction and Rietveld analysis of La1−xCaxMnO3(0

2006 ◽  
Vol 21 (1) ◽  
pp. 40-44 ◽  
Author(s):  
P. R. Sagdeo ◽  
Shahid Anwar ◽  
N. P. Lalla
Keyword(s):  
Phase Transformation ◽  
Calcium Concentration ◽  
Single Phase ◽  
Structural Phase ◽  
Rietveld Analysis ◽  
Linear Variation ◽  
X Ray Diffraction ◽  
Structural Phase Transformation ◽  
Magnetic Phases ◽  
X Ray

Single-phase samples of La1−xCaxMnO3compounds have been synthesized by solid-state reaction. Detailed Rietveld analysis of powder X-ray diffraction data showed that La1−xCaxMnO3undergoes a structural phase transformation fromR-3ctoPnmaatX=0.05–0.075. There is a linear variation of lattice parameters as a function of calcium concentration. The slope of this linear variation changes atX=0.6. A correlation between observed Mn-O bond lengths, corresponding to different compositions, and possible magnetic phases is discussed.

Neutron diffraction evidence for a structural phase transformation in stoichiometric LaD3 at 230 K

1980 ◽  
Vol 78 (1) ◽  
pp. 111-114 ◽  
Author(s):  
J.-J. Didisheim ◽  
K. Yvon ◽  
P. Fischer ◽  
W. Hälg ◽  
L. Schlapbach
Keyword(s):  
Phase Transformation ◽  
Neutron Diffraction ◽  
Structural Phase ◽  
Structural Phase Transformation

Powder X-ray diffraction and Rietveld analysis of Cd1−xCuxCr2O4(0.1≤x≤0.7)

2007 ◽  
Vol 22 (4) ◽  
pp. 340-343 ◽  
Author(s):  
L. Q. Yan ◽  
Z. W. Jiang ◽  
X. D. Peng ◽  
L. H. He ◽  
F. W. Wang
Keyword(s):  
Magnetic Properties ◽  
Phase Transformation ◽  
Structural Phase ◽  
Rietveld Analysis ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Structural Phase Transformation ◽  
X Ray ◽  
Cu Content ◽  
Tetragonal Cell

Structural properties of Cd1−xCuxCr2O4(CCCO) have been investigated by means of X-ray powder diffraction and Rietveld analysis. A structural phase transformation from Fd3m to I42d at x=0.64 has been detected. The lattice constant a of the cubic unit cell decreases rapidly with increasing Cu content up to x=0.62. At x=0.64, the cubic unit cell is compressed into a tetragonal cell and CrO6 octahedrons are distorted. With continuing Cu content increases above 0.64, the distortion of the unit cell is released slightly according to the changes in c/a. Magnetic properties of Cd1−xCuxCr2O4(x=0.1,0.3,0.5,0.7) have also been measured and are discussed.

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