Accession Number:

ADA025990

Title:

Unique Materials and Properties in the New High Pressure-Temperature Regime above 250 Kbars,

Descriptive Note:

Corporate Author:

WATERVLIET ARSENAL N Y BENET WEAPONS LAB

Report Date:

1976-01-01

Pagination or Media Count:

13.0

Abstract:

1 A new concept for generating static high pressures has resulted in the achievement of pressures exceeding 400 kbars with a sample volume of .015 cc. Substitution of diamond for tungsten carbide anvils and multiple staging should increase the attainable pressures to near 1000 kbars. 2 The developed pressure system has been successfully coupled with a cryogenic capability to 10 K. 3 An ultrasonic measurement technique has been developed for use at high pressure which by measuring shear and longitudinal velocity, yields density as a function of pressure. Also, a dielectric system has been developed for detecting of transitions and measurement of density. 4 The P-T diagram for bismuth has been developed to 140 kbars with the discovery of two new phases, one of which may be superconducting to high temperature. 5 New electronic transitions at room temperature have been discovered in GaP 216 kbars, NaCl 290 kbars, and Bi VI-IX 320 kbars. In the latter, the resistivity is less than that of copper. Author

Subject Categories:

  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE