Publication detail

Combined quantum-mechanical and Calphad approach to description of heat capacity of pure elements below room temperature

PAVLŮ, J. ŘEHÁK, P. VŘEŠŤÁL, J. ŠOB, M.

English title

Combined quantum-mechanical and Calphad approach to description of heat capacity of pure elements below room temperature

Type

journal article in Web of Science

Language

en

Original abstract

Einstein temperature(TE) wasdeterminedby fitting ofexperimentalheatcapacitydatabytheEinstein function onlywhichensuresthatitwillrepresenttheharmonicvibrationalGibbsenergyonly.Thevalues of theelectronicandanharmoniccontributionstoGibbsenergy(heatcapacity)of51elementsinstable state aredeterminedby fitting theparametersofpolynomialsdescribingthesecontributionstoSGTE data at Tlim. PolynomialspublishedbyChenandSundman(2001)wereused.Parameters a, b, and c of those polynomialshaveaparticularphysicalmeaninginthetemperatureinterval(0oToTlim) (inK) only (Tlim is thelow-temperaturelimitofvalidityofSGTEdata).Forillustration,theresultsofcalculation of heatcapacitiesinlow-temperatureregionperformedbyPHONsoftwarearepresented.Gainedther- modynamic datamakeitpossibletoperformcorrectCalphadmodelingofphasediagramsbelowroom temperature;forthispurpose,theSGTE-typeformulas(intheformofG-HSER)forGibbsenergiesof51 elements studiedareprovided.Theaimofthispaperistoshowrelativesimpleandphysicallycorrect waytoextendtheSGTEdatato0K,whichcanbesupportedbyabinitiophononcalculationsinthe future.

English abstract

Einstein temperature(TE) wasdeterminedby fitting ofexperimentalheatcapacitydatabytheEinstein function onlywhichensuresthatitwillrepresenttheharmonicvibrationalGibbsenergyonly.Thevalues of theelectronicandanharmoniccontributionstoGibbsenergy(heatcapacity)of51elementsinstable state aredeterminedby fitting theparametersofpolynomialsdescribingthesecontributionstoSGTE data at Tlim. PolynomialspublishedbyChenandSundman(2001)wereused.Parameters a, b, and c of those polynomialshaveaparticularphysicalmeaninginthetemperatureinterval(0oToTlim) (inK) only (Tlim is thelow-temperaturelimitofvalidityofSGTEdata).Forillustration,theresultsofcalculation of heatcapacitiesinlow-temperatureregionperformedbyPHONsoftwarearepresented.Gainedther- modynamic datamakeitpossibletoperformcorrectCalphadmodelingofphasediagramsbelowroom temperature;forthispurpose,theSGTE-typeformulas(intheformofG-HSER)forGibbsenergiesof51 elements studiedareprovided.Theaimofthispaperistoshowrelativesimpleandphysicallycorrect waytoextendtheSGTEdatato0K,whichcanbesupportedbyabinitiophononcalculationsinthe future.

Keywords in English

Einstein temperature; Heat capacity; SGTE data; Pure elements; Zero Kelvin; Low temperature

RIV year

2015

Released

01.12.2015

Publisher

PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND

ISSN

0364-5916

Volume

51

Number

1

Pages from–to

161–171

Pages count

11

BIBTEX


@article{BUT118708,
  author="Jana {Pavlů} and Petr {Řehák} and Jan {Vřešťál} and Mojmír {Šob},
  title="Combined quantum-mechanical and Calphad approach to description of heat capacity of pure elements below room temperature",
  year="2015",
  volume="51",
  number="1",
  month="December",
  pages="161--171",
  publisher="PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND",
  issn="0364-5916"
}