Grating groove formation in au and au-ge alloys quarterly report no. 4
Grating groove formation in gold and gold- germanium alloy films - electron micrograph pictures and spectroscopic data
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Grating groove formation in au and au-ge alloys final report, 1964
Grating groove formation in aluminum and aluminum-germanium alloys
GERMANIUM ALLOY↗
Grating groove formation in Au and Au-Ge alloys. Surface polish effects on Au mirrors Final report, 1 Apr. - 30 Sep. 1965
Electron microscopy and vacuum ultraviolet reflectometry of mirror surfaces
ELECTRON MICROSCOPY↗
Effect of Undercooling and Modified Microstructure on the Physical Properties of Material Synthesized in the Drop Tube and Drop Tower
The effects of undercooling and modified microstructure on the physical properties of synthesized materials were investigated. The objectives of this program are: (1) to determine the possible existence of metastable phases and novel physical processes on material prepared in a microgravity environment; and (2) to investigate the feasibility of fabricating advanced electronic devices using material with microstructures obtainable in a microgravity environment. The specific alloys and compounds under study are Au-Ge and immiscible alloys Nb-Ge compounds, and Ga-Bi immiscible alloys, and Ba-Pb-Bi-O. The superconducting and normal state transport properties of the materials under different pressures and in different magnetic fields were determined. The simultaneous study on the physical properties and the microstructure of material will provide information about the potential applications of materials processed in a microgravity environment.
Chu, C. W.↗
Extremely low nonalloyed and alloyed contact resistance using an InAs cap layer on InGaAs by molecular-beam epitaxy
Extremely low alloyed and nonalloyed ohmic contact resistances have been formed on n-type InAs/In(0.53)Ga(0.47)As/In(0.52)Al(0.48)As structures grown on InP(Fe) by molecular-beam epitaxy. To insure the accuracy of the small contact resistances measured, an extended transmission line model was used to extrapolate contact resistances from test patterns with multiple gap spacings varying from 1 to 20 microns. For a 150-A-thick InAs layer doped to 2 x 10 to the 18th/cu cm and a 0.1-micron-thick InGaAs layer doped to 1 x 10 to the 18th/cu cm, a specific contact resistance of 2.6 x 10 to the -8th ohm-asterisk sq cm was measured for the nonalloyed contact, while a resistance less than 1.7 x 10 to the -8th ohm-asterisk sq cm is reported for the alloyed contact. Conventional Au-Ge/Ni/Au was used for the ohmic metal contact and alloying was performed at 500 C for 50 s in flowing H2. Using a thermionic field emission model, the barrier height at the InAs/InGaAs interface was calculated to be 20 meV.
Peng, C. K.↗
Materials Data on GeAu3 by Materials Project
Au3Ge is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent Au1- sites. In the first Au1- site, Au1- is bonded to four equivalent Au1- and four equivalent Ge3+ atoms to form a mixture of distorted edge, corner, and face-sharing AuGe4Au4 tetrahedra. All Au–Au bond lengths are 2.88 Å. All Au–Ge bond lengths are 2.88 Å. In the second Au1- site, Au1- is bonded in a distorted body-centered cubic geometry to eight equivalent Au1- atoms. Ge3+ is bonded in a body-centered cubic geometry to eight equivalent Au1- atoms.
36 MATERIALS SCIENCE↗
Materials Data on GeAu3 by Materials Project
Au3Ge crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. there are two inequivalent Au1- sites. In the first Au1- site, Au1- is bonded to twelve Au1- atoms to form a mixture of face, edge, and corner-sharing AuAu12 cuboctahedra. There are six shorter (2.96 Å) and six longer (2.98 Å) Au–Au bond lengths. In the second Au1- site, Au1- is bonded to nine Au1- and three equivalent Ge3+ atoms to form distorted AuGe3Au9 cuboctahedra that share corners with eighteen equivalent AuGe3Au9 cuboctahedra, edges with twelve AuAu12 cuboctahedra, and faces with fourteen AuAu12 cuboctahedra. All Au–Au bond lengths are 2.96 Å. All Au–Ge bond lengths are 2.95 Å. Ge3+ is bonded in a 6-coordinate geometry to six equivalent Au1- atoms.
36 MATERIALS SCIENCE↗
Materials Data on Ge3Au by Materials Project
AuGe3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Au is bonded to twelve Ge atoms to form AuGe12 cuboctahedra that share corners with four equivalent AuGe12 cuboctahedra, edges with eight equivalent AuGe12 cuboctahedra, edges with sixteen equivalent GeGe8Au4 cuboctahedra, faces with four equivalent AuGe12 cuboctahedra, and faces with eight equivalent GeGe8Au4 cuboctahedra. There are four shorter (2.95 Å) and eight longer (3.07 Å) Au–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded to four equivalent Au and eight Ge atoms to form distorted GeGe8Au4 cuboctahedra that share corners with twelve equivalent GeGe8Au4 cuboctahedra, edges with eight equivalent AuGe12 cuboctahedra, edges with eight equivalent GeGe8Au4 cuboctahedra, faces with four equivalent AuGe12 cuboctahedra, and faces with ten equivalent GeGe8Au4 cuboctahedra. There are four shorter (2.95 Å) and four longer (3.07 Å) Ge–Ge bond lengths. In the second Ge site, Ge is bonded in a square co-planar geometry to four equivalent Au and eight equivalent Ge atoms.
36 MATERIALS SCIENCE↗
Materials Data on GeAu3 by Materials Project
Au3Ge is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Au1- is bonded to eight equivalent Au1- and four equivalent Ge3+ atoms to form distorted AuGe4Au8 cuboctahedra that share corners with four equivalent GeAu12 cuboctahedra, corners with fourteen equivalent AuGe4Au8 cuboctahedra, edges with six equivalent GeAu12 cuboctahedra, edges with twelve equivalent AuGe4Au8 cuboctahedra, faces with four equivalent GeAu12 cuboctahedra, and faces with sixteen equivalent AuGe4Au8 cuboctahedra. There are a spread of Au–Au bond distances ranging from 2.87–3.07 Å. There are two shorter (2.88 Å) and two longer (3.07 Å) Au–Ge bond lengths. Ge3+ is bonded to twelve equivalent Au1- atoms to form GeAu12 cuboctahedra that share corners with six equivalent GeAu12 cuboctahedra, corners with twelve equivalent AuGe4Au8 cuboctahedra, edges with eighteen equivalent AuGe4Au8 cuboctahedra, faces with eight equivalent GeAu12 cuboctahedra, and faces with twelve equivalent AuGe4Au8 cuboctahedra.
36 MATERIALS SCIENCE↗