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

Result code in 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>

Alternative codes found

RIV/00216224:14310/24:00135480

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

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

Project

<a href="/en/project/8J21AT015" target="_blank" >8J21AT015: Severe plastic deformation, a tool to create thermo-electric materials with high conversion efficiency</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

1873-4669

Volume of the periodical

976

Issue of the periodical within the volume

March

Country of publishing house

CH - SWITZERLAND

Number of pages

17

Pages from-to

173060

UT code for WoS article

001142152500001

EID of the result in the Scopus database

2-s2.0-85180539462