Surface Morphology and Lattice Misfit in Yig and La: Yig Films Grown by Lpe Method on GGG Substrate

1997 ◽  
Vol 494 ◽  
Author(s):  
Duk-yong Choi ◽  
Su-jin Chung

ABSTRACTY3Fe5O12(YIG) and La-doped YIG films were grown on the {111} GGG substrate using the PbO-B2O3 flux system. Pb, La incorporation and lattice misfit and annealing behaviors were studied. In the case of LPE growth of YIG film, lead ions from flux are substituted inevitably, and they play an important role in controlling film misfit. For a complete lattice matching, high supercooling is necessary in pure YIG growth, but this induces high defect concentration. In this experiment, La ions were added in the solution to sufficiently increase lattice parameter of the film grown under low supercooling. The concentration of substituted Pb and La were increased as the growth temperature was lowered and growth rate increased. The effective distribution coefficient of La was about 0.2 at a supercooling of 30 °C. The optimum growth conditions which bring about very small misfit were determined by measuring the misfit by double crystal diffractometer. Strain distributions of pre-annealed and annealed samples were investigated by triple crystal diffractometer.

1971 ◽  
Vol 15 ◽  
pp. 504-515 ◽  
Author(s):  
E. H. teKaat ◽  
G. H. Schwuttke

Double crystal diffractometer measurements on silicon bombarded to a fluence >1016ions/cm2with 1 MeV deuterium and 2 MeV nitrogen are reported. Such measurements provide insight into radiation damage in silicon through the observation of Bragg case pendelloesung fringes and double peak rocking curves. Bragg case pendelloesung fringes are used to determine nondestructively the projected range of ions in silicon. Double peak rocking curves are used to measure changes in lattice parameter with the ion dose. Finally, a model of radiation damage in silicon is presented.


1993 ◽  
Vol 37 ◽  
pp. 123-128 ◽  
Author(s):  
D. K. Bowen ◽  
B. K. Tanner

AbstractTwo new methods of comparison of lattice parameters are described. The first method uses a double crystal diffractometer, fitted with a specimen rotation stage. Bragg peak positions of a silicon reference and the specimen crystal are recorded for the crystals at 0 and rotated 180° about the diffraction vector. From the mean Bragg positions the lattice parameters can, in principle, be compared to parts in 106. The second method is a variant on the above, using a triple axis diffractometer. It uses a beam conditioner and monochromator to define the incident wavevector ko, and an analyser crystal to define the diffracted wave vector kh. Only the analyser motion must be accurate and stable to the arc second level. We present a detailed error analysis for the case where reference and specimen Bragg angles differ significantly. Peak location to a confidence level of 1 arc second permits absolute, traceable lattice parameter determination to several parts in 106.


Author(s):  
R H Dixon ◽  
P Kidd ◽  
P J Goodhew

Thick relaxed InGaAs layers grown epitaxially on GaAs are potentially useful substrates for growing high indium percentage strained layers. It is important that these relaxed layers are defect free and have a good surface morphology for the subsequent growth of device structures.3μm relaxed layers of InxGa1-xAs were grown on semi - insulating GaAs substrates by Molecular Beam Epitaxy (MBE), where the indium composition ranged from x=0.1 to 1.0. The interface, bulk and surface of the layers have been examined in planar view and cross-section by Transmission Electron Microscopy (TEM). The surface morphologies have been characterised by Scanning Electron Microscopy (SEM), and the bulk lattice perfection of the layers assessed using Double Crystal X-ray Diffraction (DCXRD).The surface morphology has been found to correlate with the growth conditions, with the type of defects grown-in to the layer (e.g. stacking faults, microtwins), and with the nature and density of dislocations in the interface.


1997 ◽  
Vol 30 (5) ◽  
pp. 849-853 ◽  
Author(s):  
W. Treimer ◽  
A. Höfer ◽  
H. Strothmann

The investigations of the domain structure in Ni single crystals is best performed with a double-crystal diffractometer. Conventional small-angle instruments do not have the necessary angular resolution to distinguish satellites of a main peak due to spin-dependent refraction of unpolarized neutrons by Bloch walls in Ni. With the help of a double-crystal diffractometer operating with lamellae crystals as monochromator and analyzer, the angular resolution is maintained but the intensity enhanced by a factor of 5.4. Within a series of measurements, it was possible to investigate Ni domains due to the high angular resolution of the new multi-double-crystal instrument and this improved intensity. The first results of the domain structure in (110) Ni single crystals and a good estimation of the Bloch wall thickness are given.


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