PAC spectroscopy of cadmium and cadmium-indium alloys at high temperatures

1993 ◽  
Vol 79 (1-4) ◽  
pp. 775-781 ◽  
Author(s):  
R. Hanada
Keyword(s):  
High Temperatures ◽  
Pac Spectroscopy ◽  
Indium Alloys ◽  
Cadmium Indium

scholarly journals The lattice spacings of the primary solid solutions of silver, cadmium and indium in magnesium

1940 ◽  
Vol 174 (959) ◽  
pp. 457-471 ◽  
Keyword(s):  
High Temperatures ◽  
Solid Solutions ◽  
Atomic Concentration ◽  
Factors Affecting ◽  
Silver Alloys ◽  
The Mean ◽  
High Degree ◽  
Cadmium Indium

In 1934 Hume-Rothery, Mabbott and Channel-Evans discussed the factors affecting the formation of primary solid solutions in silver and copper, and concluded that the predominant factors were the atomic diameters and valencies of the solvent and solute elements. In a later paper (Hume-Rothery and Raynor 1938) it was shown that the same considerations applied to the formation of solid solutions in magnesium, provided that due allowance was made for the highly electropositive nature of this metal. In the case of copper and silver alloys, where general valency effects are marked (Hume-Rothery et al . 1934), Hume-Rothery, Lewin and Reynolds (1936) carried out an investigation of the mean lattice spacings of primary solid solutions of cadmium, indium, tin and antimony in silver, and of zinc, gallium and germanium in copper. It was found that, to a high degree of accuracy, equal percentages of cadmium, indium, tin and anti­mony expanded the lattice of silver by amounts proportional to 2 : 3 : 4 : 6 respectively. Zinc, gallium and germanium in equal atomic concentration in copper expanded the copper lattice by amounts proportional to 3 : 4 : 4.8. These factors have been confirmed by Owen and Roberts (1939) and shown also to apply at high temperatures. The factor for germanium in copper was, however, given as 5.

In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

1991 ◽  
Vol 49 ◽  
pp. 660-661
Author(s):  
Z. L. Wang ◽  
J. Bentley
Keyword(s):  
High Temperatures ◽  
Image Resolution ◽  
Atomic Processes ◽  
Crystal Surfaces ◽  
Beam Radiation ◽  
Surface Areas ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

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