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Author |
Mattauch, S.; Heger, G.; Michel, K.H. |
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Title |
High resolution neutron and X-ray diffraction studies as a function of temperature and electric field of the ferroelectric phase transition of RDP |
Type |
A1 Journal article |
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Year |
2004 |
Publication |
Crystal research and technology |
Abbreviated Journal |
Cryst Res Technol |
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Volume |
39 |
Issue |
12 |
Pages |
1027-1054 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Neutron and high resolution X-ray diffraction investigations on perfect single crystals of RbH2PO4 (RDP), a hydrogen bonded ferroelectric of KDP type are reported. The results of crystal structure analysis from diffraction data, below and above the paraelectric – ferroelectric phase transition, support a disorder – order character Of [PO4H2](-)-groups. The tetragonal symmetry of the paraelectric phase with the double well potential of the hydrogen atoms obtained by diffraction, results simply from a time-space average of orthorhombic symmetry. According to the group – subgroup relation between the tetragonal space group 142d and the orthorhombic Fdd2 a short range order of ferroelectric clusters in the tetragonal phase is observed. With decreasing temperature the ferroelectric clusters increase and the long range interaction between their local polarisation vectors leads to the formation of lamellar ferroelectric domains with alternating polarisation directions at T-C = 147 K. From the high resolution X-ray data it is concluded that below T-C the ferroelastic strain in the (a,b)-plane leads to micro-angle grain boundaries at the domain walls. The tilt angle is enhanced by an applied electric field parallel to the ferroelectric axis. The resulting dislocations at the domain walls persist in the paraelectric phase leading to a memory effect for the arrangement of twin lamellae. With increased electric field the phase transition temperature T-C is decreased. |
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Publisher |
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Place of Publication |
Berlin |
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Wos |
000225681100001 |
Publication Date |
2004-11-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0232-1300;1521-4079; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1 |
Times cited |
12 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1; 2004 IF: 0.770 |
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Call Number |
UA @ lucian @ c:irua:94785 |
Serial |
1459 |
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Author |
Volkov, V.V.; van Heurck, C.; van Landuyt, J.; Amelinckx, S.; Zhukov, E.G.; Polulyak, E.S.; Novotortsev, V.M. |
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Title |
Electron microscopy and X-ray study of the growth of FeCr2S4 spinel single crystals by chemical vapour transport |
Type |
A1 Journal article |
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Year |
1993 |
Publication |
Crystal research and technology |
Abbreviated Journal |
Cryst Res Technol |
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Volume |
28 |
Issue |
8 |
Pages |
1051-1061 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The growth features of FeCr2S4 spinel single crystals prepared by chemical vapour transport were studied by means of scanning electron microscopy, transmission electron microscopy, high resolution electron microscopy, electron diffraction and X-ray analysis. Our results indicate that the epitaxial growth of the new phases FeCr7S12 and FeCr8S12, both based on the NiAs structure, can essentially inhibit the growth of large FeCr2S4 spinel single crystals in the octahedral habit. The new phases are fully characterised and the effects of defect ordering in these new phases are also reported. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
A1993MN86700003 |
Publication Date |
2007-01-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0232-1300;1521-4079; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
0.935 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ lucian @ c:irua:6788 |
Serial |
952 |
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Permanent link to this record |