Engineering topics

Haugland, E.

Publications and source records attributed to Haugland, E..

3 records

NASA NTRS1982

Ellipsometric studies of sputtered silicon nitride on n-GaAs

Ellipsometry, which is the study of optical systems through their effect on polarized light, is a nondestructive technique offering extremely high sensitivity and in situ operation. One of the intriguing possibilities is to make use of the high sensitivity of ellipsometry for studying the very thin interface between an insulating film and a semiconductor substrate. Researchers have been especially interested in native or anodic oxides. In a recent study, Aspnes and Theeten used ellipsometry to study the interface between silicon and its thermally grown oxide, SiO2. These authors were able to conclude that the interface consisted of a 7 +/- 2 A graded region of atomically mixed silicon and oxygen. In this paper we report both analysis and experimental results for the system: sputtered silicon nitride on (100) n-type gallium arsenide.

Peng, Y. K.↗

NASA NTRS1981

Effective masses, relaxation times, and carrier mobilities in some chloride intercalants of graphite

The effective masses, carrier scattering times and carrier mobilities have been measured in selected graphite intercalation compounds using the Shubnikov-de Haas effect at a series of temperatures between 4 and 50 K. Effective masses are less than or equal to 0.1 of the free-electron mass, scattering times are about 10 to the -13th/s and carrier mobilities are on the order of 10,000 sq cm/V s.

Woollam, J. A.↗

NASA NTRS1980

Critical currents in A-15 structure Nb3Al converted from cold-worked bcc structure

The paper considers critical currents in A-15 structure Nb3Al converted from a cold-worked bcc structure. Nb3Al prepared in the ductile phase by quenching and mechanical working followed by conversion to the A-15 structure could carry currents above 10 to the 9th power A/sq m in fields near 20 T. These critical currents are comparable to those of Nb3Ge and V3Ga which are closest competing materials for use in high fields; further enhancement of the critical current is possible if thermal treatments are optimized.

Woollam, J. A.↗