THE STUDY OF THE STRUCTURAL AND TRANSFORMATION CHARACTERISTICS OF THE PRESSURE INDUCED POLYMORPHS IN BISMUTH,

Abstract

It is known from the early work of Bridgman that the two lowest pressure transitions (I-II and IIIII) are accompanied by substantial and abrupt changes in resistivity and volume, the former being highly desirable for pressure calibration purposes. However, unlike the temperature induced allotropic transformations observed in such elements as lithium, cobalt, tin, etc., there is little actually known about many of the characteristics of the pressure induced transitions. This current work involves an examination of the structural and transformation characteristics of the bismuth I-II and II-III transitions under hydrostatic pressures. The relationship of initial structure to the transformation pressure, rate, resistivity change, and resultant structure is discussed. It is shown that the transition pressure and transformation rate are independent of the presence of grain boundaries and associated anisotropy induced deformation. An observed hysteresis in both the I-II and II-III transitions is shown. (Author)

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1963
Accession Number
AD0430167

Entities

People

  • A. P. Lee
  • T. E. Davidson

Tags

DTIC Thesaurus Topics

  • Anisotropy
  • Boundaries
  • Calibration
  • Dynamic Pressure
  • Grain Boundaries
  • Hydrostatic Pressure
  • Hysteresis
  • Static Pressure
  • Transitions

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.