Accession Number:

AD0625428

Title:

PHASE EQUILIBRIUM STUDIES OF GERMANIUM AND SILICON AT HIGH PRESSURES.

Descriptive Note:

Technical rept. (Doctoral thesis),

Corporate Author:

PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB

Personal Author(s):

• Bates,Carl Hobart

Report Date:

1966-03-01

Pagination or Media Count:

79.0

Abstract:

The phase relations of the high pressure polymorphic modifications of germanium were studied up to pressures of 150 kbars with the use of the opposed anvil apparatus. Long times at pressure up to 6 weeks favored the attainment of equilibrium and enabled the preparation of a new high pressure phase Ge-IV with the body centered cubic structure. The triple point between Ge-I diamond structure, Ge-III body centered tetragonal and Ge-IV body centered cubic has been established at 75 kbars and 430C. A good estimate of the triple point between Ge-I, Ge-IV and liquid is 93 kbars and 630C. Another new phase with the simple cubic structure has been detected for the first time although its relations to the other polymorphs of germanium has not been established. Extension of this work into the Ge-Si system enabled onstruction of a 150C isothermal section and a 10 mole Si isoplethal section through the P-T-X-volume for the system. Author

Descriptors:

• *GERMANIUM
• *SILICON
• TRANSITIONS
• OPTICAL ANALYSIS

Subject Categories:

• Properties of Metals and Alloys
• Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE