Constitution, physical properties and thermodynamic modeling of the Hf-Mn system

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F24%3A00579738" target="_blank" >RIV/68081723:_____/24:00579738 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14310/24:00135480

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0925838823043633?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0925838823043633?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jallcom.2023.173060" target="_blank" >10.1016/j.jallcom.2023.173060</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Constitution, physical properties and thermodynamic modeling of the Hf-Mn system

Popis výsledku v původním jazyce

The Hf-Mn system is of a long-time interest due to the intermetallic Laves phase HfMn2, a hydrogen storage material. Although this system has been experimentally investigated by several authors and critical reviews and thermodynamic modelling have been performed, there is still a lack of reliable information, particularly as the phase HfMn (sometimes labelled as Hf3Mn2 or Hf2Mn) is suspected to be oxygen stabilized. This work includes a thorough investigation of the Hf-Mn phase equilibria employing diffusion zones, thermal analysis, powder and single crystal X-ray analyses, analytical electron microscopy as well as physical property studies of the Laves phase (magnetic susceptibility, specific heat, electrical resistivity and mechanical properties). The phase near HfMn was shown (TEM, WDX electron microprobe data, X-ray single crystal analysis) to be an oxygen stabilized phase with the formula Hf3+xMn3−xO1−y (defect η-W3Fe3C type). Properties such as magnetic susceptibility/magnetization, 2–300 K, specific heat (2–1100 K), electrical resistivity (2–300 K) classify HfMn2 as a metallic spin-fluctuation system with itinerant paramagnetism, originating from 3d states at Mn-sites and local moment paramagnetism of antisite Mn-atoms at Hf-sites. Mechanical properties (elastic moduli from density functional theory (DFT) and nanoindentation as well as hardness) group the Laves phase among rather hard and brittle intermetallics. DFT modeling revealed that Hf3+xMn3−x is thermodynamically unstable, but significant gains in enthalpy of formation arise from the inclusion of oxygen atoms, stabilizing the η phase. All phase diagram and DFT data together with the former literature information were used for the thermodynamic CALPHAD-type modelling of the Hf-Mn system.

Název v anglickém jazyce

Constitution, physical properties and thermodynamic modeling of the Hf-Mn system

Popis výsledku anglicky

The Hf-Mn system is of a long-time interest due to the intermetallic Laves phase HfMn2, a hydrogen storage material. Although this system has been experimentally investigated by several authors and critical reviews and thermodynamic modelling have been performed, there is still a lack of reliable information, particularly as the phase HfMn (sometimes labelled as Hf3Mn2 or Hf2Mn) is suspected to be oxygen stabilized. This work includes a thorough investigation of the Hf-Mn phase equilibria employing diffusion zones, thermal analysis, powder and single crystal X-ray analyses, analytical electron microscopy as well as physical property studies of the Laves phase (magnetic susceptibility, specific heat, electrical resistivity and mechanical properties). The phase near HfMn was shown (TEM, WDX electron microprobe data, X-ray single crystal analysis) to be an oxygen stabilized phase with the formula Hf3+xMn3−xO1−y (defect η-W3Fe3C type). Properties such as magnetic susceptibility/magnetization, 2–300 K, specific heat (2–1100 K), electrical resistivity (2–300 K) classify HfMn2 as a metallic spin-fluctuation system with itinerant paramagnetism, originating from 3d states at Mn-sites and local moment paramagnetism of antisite Mn-atoms at Hf-sites. Mechanical properties (elastic moduli from density functional theory (DFT) and nanoindentation as well as hardness) group the Laves phase among rather hard and brittle intermetallics. DFT modeling revealed that Hf3+xMn3−x is thermodynamically unstable, but significant gains in enthalpy of formation arise from the inclusion of oxygen atoms, stabilizing the η phase. All phase diagram and DFT data together with the former literature information were used for the thermodynamic CALPHAD-type modelling of the Hf-Mn system.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/8J21AT015" target="_blank" >8J21AT015: Intenzivní plastická deformace - cesta k termoelektrickým materiálům s vysokou konverzní účinností</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

1873-4669

Svazek periodika

976

Číslo periodika v rámci svazku

March

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

17

Strana od-do

173060

Kód UT WoS článku

001142152500001

EID výsledku v databázi Scopus

2-s2.0-85180539462