Az öndiffúzió nyomásfüggése B2 típusú intermetallikus vegyületekben

Translated title of the contribution: Pressure dependence of the self-diffusion in B2 intermetallic phases

Gábor Erdélyi, Dezso Beke

Research output: Contribution to journalArticle

Abstract

We have experimentally shown that the activation volume for Ni diffusion in NiTi B2 compound is close to zero. In order to interpret our experimental findings we estimated theoretically the pressure dependence of point defect concentrations in B2 systems. The effective formation volume of vacancies shows asymmetrical character about stoichiometry: on the Ni-rich side the Ni vacancy concentration can be described by an exp{-pΔV/RT}-type function, on the Al-rich side, it shows a more complex behaviour. At low pressures the Ni-vacancy concentration is independent of pressure, the effective formation volume is zero, above a critical pressure, where the vacancy replacement by Al-antisites is completed, the vacancy concentration will be pressure dependent. Experimental observation of the expected asymmetry of the effective formation volume could help to identify the defect structure and the operating diffusion mechanism(s).

Original languageHungarian
Pages (from-to)427-432
Number of pages6
JournalMagyar Kemiai Folyoirat, Kemiai Kozlemenyek
Volume107
Issue number10
Publication statusPublished - Oct 1 2001

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ASJC Scopus subject areas

  • Chemistry(all)

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