摘要:

The temperature dependence of the mobility of two‐dimensional hole systems at modulation‐doped GaAs‐(AlGa)As heterojunctions is determined. Its shape follows closely the equivalent curve for high‐purityp‐type bulk GaAs. Low‐temperature mobilities beyond 4×104cm2/Vs are found for areal hole densities of 5×1011cm−2. The equivalent scattering times reach those of the best modulation‐doped electron systems. In the temperature range where acoustic mode scattering prevails aT−3/4dependence was observed. Studies under light illumination could not detect any persistent photoconductive effect in two‐dimensional holes.

ISSN:0003-6951    

DOI:10.1063/1.94580

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The effects of reactive I+ion beams, derived from a source of solid elemental I, on In‐containing compound semiconductors have been investigated using transmission electron microscopy. The results are compared with the effects produced by beams of Ar+and Xe+inert gas ions. It is shown that the surface accumulation of metallic In due to the disproportionation normally associated with ion milling of these materials can be eliminated by the use of I+ion beams. Transmission electron microscope specimens in cross‐sectional configuration are used to demonstrate the excellent results which may be obtained by I+ion milling of InP and InSb.

ISSN:0003-6951    

DOI:10.1063/1.94582

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Techniques for passivating In0.53Ga0.47As, InGaAsP, InP, and InGaAsP/InPp‐njunction structures with polyimide have been developed. Low stable leakage current is maintained for prolonged bias, even after exposure to high temperatures (∼320 °C) during packaging. 150‐&mgr;m‐diam In0.53Ga0.47As photodiodes with a breakdown voltage of ∼50 V were passivated with polyimide and were found to consistently have leakage currents of ∼10 nA at a 20‐V bias.Details of the passivation process are given.

ISSN:0003-6951    

DOI:10.1063/1.94583

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We have explored the hard magnetic properties of melt‐spun Nd‐Fe‐B alloys. A maximum energy product of 14.1 MG Oe has been observed, the highest value ever reported for a light rare earth‐iron material. X‐ray analyses indicate that the alloys exhibiting optimum characteristics are comprised of roughly spherical crystallites of an equilibrium Nd‐Fe‐B intermetallic phase. The observed grain sizes are in or near the estimated single‐domain range, suggesting that the coercivity arises principally from the formation of single‐domain particles.

ISSN:0003-6951    

DOI:10.1063/1.94584

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A comment on lattice location of chromium by ion channeling and detection of x‐ray signals of Cr‐K&agr; excited by 1‐MeV H+from a Cr‐doped GaAs is presented.

ISSN:0003-6951    

DOI:10.1063/1.94585

出版商:AIP    

年代:1984

数据来源: AIP