An X-ray Topographic Study of the Paraelectric-to-Ferroelectric Phase Transformation in Nearly Perfect Single Crystals of Ammonium Sulfate

1995 ◽  
Vol 28 (2) ◽  
pp. 168-188 ◽  
Author(s):  
H. L. Bhat ◽  
H. Klapper ◽  
K. J. Roberts
Keyword(s):  
Phase Transformation ◽  
Single Crystals ◽  
Ammonium Sulfate ◽  
Ferroelectric Phase ◽  
X Ray

Direct observation of monoclinic ferroelectric phase and domain switching process in (K0.25Na0.75)NbO3 single crystals

CrystEngComm ◽  
2015 ◽  
Vol 17 (14) ◽  
pp. 2872-2877 ◽  
Author(s):  
Hao Deng ◽  
Haiwu Zhang ◽  
Xiangyong Zhao ◽  
Chao Chen ◽  
Xi'an Wang ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Single Crystals ◽  
Direct Observation ◽  
Ferroelectric Phase ◽  
Domain Switching ◽  
Polarized Light ◽  
Switching Process ◽  
X Ray Diffraction ◽  
X Ray

The domain-switching process of monoclinic K0.25Na0.75NbO3 single crystals were studied by in situ polarized light microscopy and X-ray diffraction.

Phase Transformations in Lutetium Borides at Heating in Vacuum

2011 ◽  
Vol 172-174 ◽  
pp. 464-469 ◽  
Author(s):  
Anatoliy Taran ◽  
Daniel Voronovich ◽  
Natalya Shitsevalova ◽  
Ganna Levchenko ◽  
Volodymyr Filipov ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Phase Transformation ◽  
Surface Layer ◽  
Single Crystal ◽  
Phase Transformations ◽  
Single Crystals ◽  
X Ray ◽  
Before And After ◽  
Spontaneous Phase ◽  
Crystal Bulk

The LuB12 ® LuB4 ® LuB2 phase transformations on annealing in vacuum (T=(1400÷1800) K, p < 10-2 Pa) are investigated with use of the parent single crystals. SEM and X-ray researches of the corresponding lutetium boride single crystals were carried out before and after their annealing. It is shown that the LuB12 → LuB4 phase transformation takes place in surface layer and transition region spreads inwards the single crystal bulk with time. According to the assessed Lu-B phase diagram the LuB4 phase transformation into other individual phases is impossible, and at first it is shown that under corresponding conditions the LuB4 → LuB2 spontaneous phase transformation takes place both on the surface and in the LuB4 single crystal bulk.

Crystal structure, thermal expansion and elastic properties of triclinic betaine hydrogen ammonium sulfate, ((CH3)3NCH2COOH)NH4SO4

1996 ◽  
Vol 211 (2) ◽  
Author(s):  
S. Haussühl ◽  
J. Schreuer
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Ammonium Sulfate ◽  
Elastic Properties ◽  
Structure Analysis ◽  
Optical Quality ◽  
X Ray

AbstractLarge single crystals of optical quality of betaine hydrogen ammonium sulfate have been grown from aqueous solutions. An X-ray structure analysis yielded space group

Zone-axis ALCHEMI for the rapid assessment of site occupancies in garnets

1986 ◽  
Vol 44 ◽  
pp. 706-707
Author(s):  
M.T. Otten ◽  
P.R. Buseck
Keyword(s):  
Single Crystals ◽  
Rapid Assessment ◽  
Site Occupancy ◽  
Zone Axis ◽  
Synthetic Compounds ◽  
X Ray ◽  
Large Group ◽  
Crystallographic Planes

ALCHEMI (Atom Location by CHannelling-Enhanced Microanalysis) is a TEM technique for determining site occupancies in single crystals. The method uses the channelling of incident electrons along specific crystallographic planes. This channelling results in enhanced x-ray emission from the atoms on those planes, thereby providing the required site-occupancy information. ALCHEMI has been applied with success to spinel, olivine and feldspar. For the garnets, which form a large group of important minerals and synthetic compounds, the channelling effect is weaker, and significant results are more difficult to obtain. It was found, however, that the channelling effect is pronounced for low-index zone-axis orientations, yielding a method for assessing site occupancies that is rapid and easy to perform.

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