HIGH-TEMPERATURE X-RAY-DIFFRACTION STUDIES OF LATTICE-DYNAMICS IN NI3(FE,NB) ORDERED ALLOYS

MEKHRABOV A.

ACTA PHYSICA POLONICA A, vol.85, no.3, pp.571-578, 1994 (SCI-Expanded, Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 85 Issue: 3
  • Publication Date: 1994
  • Doi Number: 10.12693/aphyspola.85.571
  • Journal Name: ACTA PHYSICA POLONICA A
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Compendex, INSPEC
  • Page Numbers: pp.571-578
  • Middle East Technical University Affiliated: Yes

Abstract

A study is performed on characteristics of lattice dynamics in the initially ordered ternary Ni3(Fe1-xNbx) (x = 0 to 10 at.%) alloys using high temperature X-ray diffractometry for the temperature range from 300 K to 1300 K. Aspects investigated included temperature and concentration dependencies of the full mean square atomic displacements U(f)2BAR, the Debye characteristic temperature THETA(D), and linear thermal expansion coefficient alpha. It is found that the U(f)2BAR, THETA(D), and alpha parameters show anomalous change at temperatures where the alloys are subjected to order-disorder phase transitions. It is further found that Nb addition results in the considerable increase in the parameters U(f)2BAR and alpha and decrease in THETA(D). Moreover, the addition of Nb stabilizes Ni3Fe ordered structure and shifts the order-disorder transition to higher temperature.