liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
A first principles study of the thermodynamics of phase separating systems -The examples RhPd and AlZn-
Linköping University, Department of Physics, Chemistry and Biology.
2009 (English)Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

A screened GPM approach in an EMTO-CPA framework was investigated in order to study its ability of describing transition temperatures in phase separating systems, i. e. systems giving either a random or a cluster structure depending on the temperature and the relative concentration of the ingoing atoms of the binary alloy used for the study. A motivation for the study is that the method works well for ordering systems, i. e. systems giving either a random or ordered structure dependent on the temperature and the relative concentration of the components in the binary alloy. Thereby is it of interest to find out the methods capacity in phase separating systems. The so called GPM potentials derived in the approach were applied in statistical Monte Carlo simulations for this purpose. The systems chosen for the investigation were the RhPd and the AlZn binary alloy systems. For both systems the method showed acceptable accuracy when properties as lattice parameter and mixing enthalpy were calculated. The quality of the derived GPM potentials has also been checked by calculating ordering energy for different ordered structures; directly from first principles calculations and from the GPM approach. The results were in acceptable agreement and thereby indicating that the GPM potentials were reliable. The transition temperatures in the RhPd phase diagram, derived by the statistical Monte Carlo simulations showed anyway deviation from experimental results. The error in the predictions might be due to the existing concentration dependencies in the GPM potentials.The conclusion from this study is that the Monte Carlo scheme might be inconvenient in order to handle the concentration dependencies seen in the GPM potentials.

Place, publisher, year, edition, pages
2009. , 54 p.
Keyword [en]
Density Functional Theory, Phase Separating Alloy, Coherent Potential Approximation, Exact Muffin Tin Orbital method, Generalized Perturbation Method
National Category
Condensed Matter Physics
URN: urn:nbn:se:liu:diva-18517ISRN: LITH-IFM-A-EX--09/2125--SEOAI: diva2:224209
Available from: 2009-06-18 Created: 2009-05-29 Last updated: 2009-06-18Bibliographically approved

Open Access in DiVA

fulltext(942 kB)359 downloads
File information
File name FULLTEXT01.pdfFile size 942 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
Department of Physics, Chemistry and Biology
Condensed Matter Physics

Search outside of DiVA

GoogleGoogle Scholar
Total: 359 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 176 hits
ReferencesLink to record
Permanent link

Direct link