Antiphase domains in?-eucryptite (LiAlSiO4)

1976 ◽  
Vol 63 (6) ◽  
pp. 294-294 ◽  
Author(s):  
W. F. M�ller ◽  
H. Schulz
Keyword(s):  
Antiphase Domains

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

Formation process of periodic non-conservative antiphase boundary structure in L-Pd5Ce

1990 ◽  
Vol 48 (4) ◽  
pp. 162-163
Author(s):  
Masaru Itakura ◽  
Noriyuki Kuwano ◽  
Kensuke Oki
Keyword(s):  
Formation Process ◽  
Domain Size ◽  
Antiphase Boundary ◽  
Boundary Structure ◽  
Temperature Phase ◽  
Arc Melting ◽  
Iced Water ◽  
Antiphase Domains ◽  
Low Temperature Phase ◽  
Degree Of Order

The low temperature phase of Pd5Ce (L-Pd5Ce) has a one-dimensional long period superstructure (1D-LPS) derived from Ll2. The periodic antiphase boundaries (APBs) are parallel to (110) planes and have a shift vector of 1/2[110]. Hereafter, the indices are referred to the basic lattices of Ll2 As insertion of the APB causes a change in composition, such an APB is called “non-conservative”. Then, a domain size M depends upon the Ce concentration in the alloy. It was found that M increases also with temperature. The temperature dependency of M is attributed to a change of the degree of order within the antiphase domains. In this work, morphology of the non-conservative APBs is observed to clarify the formation process of the 1D-LPS.The alloy of Pd-16.7 at%Ce was prepared by arc melting in argon atmosphere. Disc specimens made from the alloy ingot were first held at 985 K for 260 ks and quenched in iced water to obtain the state of M=∞ or Ll2, followed by annealing for various lengths of time. The annealing temperature was 873 K where the equilibrium value for M is about 3 in unit of (110) lattice spacing of Ll2. Observation was carried out using microscopes JEM-2000FX, JEM-4000EX (HVEM Lab., Kyushu Univ.) and JEM-2000EX (Dept. of Mater. Sci. Tech., Kyushu Univ.).

On the origin and growth of antiphase domains in anorthite

1984 ◽  
Vol 107 (3) ◽  
pp. 489-494 ◽  
Author(s):  
Wolfgang F. Müller ◽  
Ralf J. John ◽  
Herbert Kroll
Keyword(s):  
Antiphase Domains

Real-space imaging of ferroelectric and structural antiphase domains in hexagonal YMnO3

2013 ◽  
Vol 62 (7) ◽  
pp. 1077-1081 ◽  
Author(s):  
K. Kobayashi ◽  
H. Kamo ◽  
K. Kurushima ◽  
Y. Horibe ◽  
S. -W. Cheong ◽  
...  
Keyword(s):  
Real Space ◽  
Antiphase Domains

Experimental Evidence of Ca Segregation to Antiphase Boundaries in Pigeonite

2001 ◽  
Vol 7 (S2) ◽  
pp. 254-255
Author(s):  
KT Moore ◽  
DR Veblen ◽  
JM Howe
Keyword(s):  
Experimental Evidence ◽  
Thermal History ◽  
Igneous Rocks ◽  
Cooling History ◽  
Antiphase Boundaries ◽  
Cooling Rates ◽  
History Of ◽  
Antiphase Domains

For over 30 years geologists have been trying to better understand antiphase domains (APD) and boundaries (APB) in pigeonite in hopes of using them as markers for the thermal history of the rocks in which they are found. The ability to know the cooling history of igneous rocks is of great interest to geologists and pigeonite has received special attention on this matter because it has exsolution (precipitation) and antiphase domains (APD), both of which can be used as possible thermal markers. APDs in pigeonite arise because of the C2/c → P21/c transformation that occurs upon cooling. When multiple APDs nucleate, grow, and impinge upon one another, they are either in registry or have a translational discrepancy of ½(a+b). The size of the APDs can be used as a qualitative marker of cooling rates, since slowly cooled pigeonites favor large APDs and rapidly cooled pigeonites favor small APDs.

Phase retrieval in coherent diffraction from Cu3Au antiphase domains

1999 ◽  
Author(s):  
John A. Pitney ◽  
Ivan A. Vartaniants ◽  
Ian K. Robinson
Keyword(s):  
Phase Retrieval ◽  
Antiphase Domains

Additivity of Hardening by Nanolamellar Structure and Antiphase Domain in Ti-39at%Al Single Crystals

2008 ◽  
Vol 1086 ◽  
Author(s):  
Yuichiro Koizumi ◽  
Yoritoshi Minamino ◽  
Takayuki Tanaka ◽  
Kazuki Iwamoto
Keyword(s):  
Lamellar Structure ◽  
Antiphase Domain ◽  
Dislocation Motion ◽  
Additional Stress ◽  
Slip Direction ◽  
Prism Slip ◽  
Screw Dislocations ◽  
Lamellar Structures ◽  
Mixed Microstructure ◽  
Antiphase Domains

AbstractA mixed microstructure of antiphase domains (APD) and fine lamellar structure were introduced in a Ti-39at%Al single crystal and it was examined whether the APD hardening works even in nano-scaled lamellar structures. The hardness increases with decreasing APD size even where the L is smaller than 100 nm below which the hardening by lamellar refining saturates. The mechanism of the additivity of strengthening by APD and lamellar structure is discussed in the context of the geometries of slip direction, lamellar boundaries and APD boundaries (APDBs). For {1100}<1120> prism slip (the easiest slip system of α2-Ti3Al), the lamellar boundaries are parallel to the slip direction, and therefore they interrupt the motion of screw dislocations effectively. On the other hand, APDBs inclined from lamellar boundaries can effectively obstruct the dislocation motion regardless of the dislocation character because the shear of such APDBs results in the formation of step-like APDBs on the slip-plane and requires additional stress for dislocation motion whereas APDBs parallel to the slip direction can be sheared without forming such a step-like APDB. Accordingly, APDs and lamellar structure can contribute to the strengthening complementarily.

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