Accession Number:

AD0258132

Title:

LOW-TEMPERATURE SPONTANEOUS TRANSFORMATIONS IN FINE-GRAINED ALKALI METALS

Descriptive Note:

Corporate Author:

OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS

Personal Author(s):

• ALEXOPOULOS,K.D.
• SHAW,C.H.

Report Date:

1961-02-01

Pagination or Media Count:

1.0

Abstract:

IN THE COURSE OF DIFFRACTION EXPERIMENTS ON LITHIUM, SODIUM, AND POTASSIUM COOLED TO 1.4 K, observations were made on the quantity of transformed phase and the temperture region in which this transformation occurs. Two samples of lithium were used. The first was of very pure metal of rather large grain size the second was less pure, but fine-grained. Both samples showed spontaneous transformation to hcp hexagonal close-packed and fcc. The behavior of a fine-grained sodium sample in the same temperature range was quite different. Upon the first cooling to 1.4 K, no low-temperature phase appeared. After being warmed to 77 K and again cooled, the hcp phase appeared in considerable quantity. No spontaneous transformation was detected in a fine-grained sample of potassium to 1.4 K. Author

Descriptors:

• *ALKALI METALS
• *CRYSTAL STRUCTURE
• *TRANSFORMATIONS
• CRYSTALS
• GRAIN STRUCTURES(METALLURGY)
• LITHIUM
• CRYOGENICS
• POTASSIUM
• SODIUM
• X RAY DIFFRACTION

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE