Issue |
Europhys. Lett.
Volume 42, Number 6, June II 1998
|
|
---|---|---|
Page(s) | 649 - 654 | |
Section | Condensed matter: electronic structure, electrical, magnetic and optical properties | |
DOI | https://doi.org/10.1209/epl/i1998-00300-9 | |
Published online | 01 September 2002 |
On the fcc-B2 transformation in CuPd alloys
Dipartimento di Fisica and Unità INFM,
Università di Messina, Salita Sperone 31, 98166 Messina, Italy
Received:
26
January
1998
Accepted:
30
April
1998
At high temperatures the alloy forms a
fcc solid solution phase that at 770 K undergoes a bainitic
transformation into a B2 phase, bcc based and chemically ordered.
On the basis of first-principles calculations performed along the
appropriate Bain paths, both for the ordered and disordered alloys,
we find that this phase transition is due to the competition
between the band electronic energy and the electrostatic interactions,
the former favouring fcc, the latter bcc geometrical arrangements.
Below the transition temperature the chemical ordering, driven
by the conventional Fermi surface mechanism, causes an increase
of the charge transfer and changes the shape of the energy curve along
the Bain path. As a result, a plastic deformation of the geometrical
lattice occurs. In this scenario, the coupling between concentration
and uniaxial strain fluctuations plays a fundamental role and
the key physical quantity is the charge transfer.
PACS: 71.15.Nc – Total energy and cohesive energy calculations / 64.70.Kb – Solid-solid transitions / 71.20.Be – Transition metals and alloys
© EDP Sciences, 1998
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.