Entropy: A controversy between experiment and calculations in
grain boundary segregation

J 2025

Entropy: A controversy between experiment and calculations in grain boundary segregation

LEJCEK, Pavel a Mojmír ŠOB

Základní údaje

Originální název

Entropy: A controversy between experiment and calculations in grain boundary segregation

Autoři

LEJCEK, Pavel a Mojmír ŠOB

Vydání

PROGRESS IN MATERIALS SCIENCE, OXFORD, PERGAMON-ELSEVIER SCIENCE LTD, 2025, 0079-6425

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10403 Physical chemistry

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 40.000 v roce 2024

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/25:00141952

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

Grain boundary segregation; Experiment; Calculations; Entropy; Energy; Enthalpy; Grain boundary migration; Intergranular embrittlement

Štítky

14313010, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 8. 9. 2025 17:35, Mgr. Pavla Foltynová, Ph.D.

Anotace

V originále

Grain boundary segregation is one of the crucial phenomena affecting the properties of the materials and their technological applications. However, 50 years since starting its intensive study, there still remain open questions and controversies related to this phenomenon. Probably, the most serious uncertainty consists in understanding the segregation entropy. While this term seems to result directly from experimental studies of temperature dependence of chemical composition of grain boundaries, it is mostly neglected in theoretical calculations. This negligence arises from the fact that most of the first-principles calculations are performed at the temperature of 0 K and, therefore, the segregation entropy is usually not evaluated. Consequently, it is supposed that its contribution at enhanced temperatures is negligible which is supported by scarce calculations of the vibrational entropy of grain boundary segregation. Another question discussed presently between theoreticians on one hand and experimenters on the other hand deals with physical meaning of the values of the thermodynamic quantities determined from the average grain boundary concentration. This paper summarizes the present knowledge on the segregation entropy in metallic hosts and documents some issues in which the segregation entropy plays important and irreplaceable role. These issues are represented by the enthalpy-entropy compensation effect, by the method of prediction of grain boundary segregation and by comparison of calculated results and experimental or predicted data. The role of the entropy is also crucial in the recently discussed cases of the entropy-dominated and entropy-driven grain boundary segregation. Finally, collective processes related to grain boundaries - grain boundary migration and intergranular fracture - are discussed suggesting that these processes, based on coordinated behavior of numerous neighbor atoms in the grain boundary core, will be better characterized by average values of characteristic quantities rather than by the values of these quantities for individual sites.

Citovat

LEJCEK, Pavel a Mojmír ŠOB. Entropy: A controversy between experiment and calculations in grain boundary segregation. PROGRESS IN MATERIALS SCIENCE. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD, 2025, roč. 151, MAY, s. 1-38. ISSN 0079-6425. Dostupné z: https://doi.org/10.1016/j.pmatsci.2025.101431.

@article{2515698,
   author = {Lejcek, Pavel and Šob, Mojmír},
   article_location = {OXFORD},
   article_number = {MAY},
   doi = {https://doi.org/10.1016/j.pmatsci.2025.101431},
   keywords = {Grain boundary segregation; Experiment; Calculations; Entropy; Energy; Enthalpy; Grain boundary migration; Intergranular embrittlement},
   language = {eng},
   issn = {0079-6425},
   journal = {PROGRESS IN MATERIALS SCIENCE},
   title = {Entropy: A controversy between experiment and calculations in grain boundary segregation},
   url = {https://www.sciencedirect.com/science/article/pii/S0079642525000064?via%3Dihub},
   volume = {151},
   year = {2025}
}

TY  - JOUR
ID  - 2515698
AU  - Lejcek, Pavel - Šob, Mojmír
PY  - 2025
TI  - Entropy: A controversy between experiment and calculations in grain boundary segregation
JF  - PROGRESS IN MATERIALS SCIENCE
VL  - 151
IS  - MAY
SP  - 1-38
EP  - 1-38
PB  - PERGAMON-ELSEVIER SCIENCE LTD
SN  - 00796425
KW  - Grain boundary segregation
KW  - Experiment
KW  - Calculations
KW  - Entropy
KW  - Energy
KW  - Enthalpy
KW  - Grain boundary migration
KW  - Intergranular embrittlement
UR  - https://www.sciencedirect.com/science/article/pii/S0079642525000064?via%3Dihub
N2  - Grain boundary segregation is one of the crucial phenomena affecting the properties of the materials and their technological applications. However, 50 years since starting its intensive study, there still remain open questions and controversies related to this phenomenon. Probably, the most serious uncertainty consists in understanding the segregation entropy. While this term seems to result directly from experimental studies of temperature dependence of chemical composition of grain boundaries, it is mostly neglected in theoretical calculations. This negligence arises from the fact that most of the first-principles calculations are performed at the temperature of 0 K and, therefore, the segregation entropy is usually not evaluated. Consequently, it is supposed that its contribution at enhanced temperatures is negligible which is supported by scarce calculations of the vibrational entropy of grain boundary segregation. Another question discussed presently between theoreticians on one hand and experimenters on the other hand deals with physical meaning of the values of the thermodynamic quantities determined from the average grain boundary concentration. This paper summarizes the present knowledge on the segregation entropy in metallic hosts and documents some issues in which the segregation entropy plays important and irreplaceable role. These issues are represented by the enthalpy-entropy compensation effect, by the method of prediction of grain boundary segregation and by comparison of calculated results and experimental or predicted data. The role of the entropy is also crucial in the recently discussed cases of the entropy-dominated and entropy-driven grain boundary segregation. Finally, collective processes related to grain boundaries - grain boundary migration and intergranular fracture - are discussed suggesting that these processes, based on coordinated behavior of numerous neighbor atoms in the grain boundary core, will be better characterized by average values of characteristic quantities rather than by the values of these quantities for individual sites.
ER  -

LEJCEK, Pavel a Mojmír ŠOB. Entropy: A controversy between experiment and calculations in grain boundary segregation. \textit{PROGRESS IN MATERIALS SCIENCE}. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD, 2025, roč.~151, MAY, s.~1-38. ISSN~0079-6425. Dostupné z: https://doi.org/10.1016/j.pmatsci.2025.101431.

Přehled o publikaci