uk

mfflogo 

Search

News

Ernst Bauer: Improved thermoelectric performance of bulk and thin film full-Heusler systems based on Fe2VAl
Begin: 20.01.2021, 14:10
Location: ZOOM Meeting ID: 958 0426 7376

Volodymyr Buturlim: Uranium in metastable systems: structure, magnetism, superconductivity
Begin: 27.01.2021, 14:10
Location: ZOOM Meeting ID: 958 0426 7376

Lukáš Nádvorník: Terahertz and optical spintronics in ferro- and antiferromagnets
Begin: 24.02.2021, 14:10
Location: ZOOM Meeting ID: 958 0426 7376

 
Title: Volodymyr Buturlim: Uranium in metastable systems: structure, magnetism, superconductivity
Number: 4/21
Status: Not exceeded
Begin: Wednesday, 27.01. 2021, 14:10
Tutor: Vladimír Sechovský
Location: ZOOM Meeting ID: 958 0426 7376


new logo

  

We have a pleasure to invite you to attend the joint seminar
of the Department of Condensed Matter Physics (DCMP)
and the Materials Growth and Measurement Laboratory (MGML) http://mgml.eu.

 

Program

 

Uranium in metastable systems: structure, magnetism, superconductivity

lecture given by:

Volodymyr Buturlim

Department of Condensed Matter Physics, Faculty of Mahtematics and Physics, Charles University,
Ke Karlovu 5, 121 16 Prague 2, Czech Republic

 

https://cesnet.zoom.us/j/95804267376
Meeting ID: 958 0426 7376 

on Wednesday, 27.1. 2021 from 14:10 CET (13.10 UTC) 


Passcode will be provided on request at  This e-mail address is being protected from spambots. You need JavaScript enabled to view it

 

Vladimír Sechovský
On behalf of the DCMP and MGML


Abstract 

Uranium hydrides have a long history. Despite being the first discovered actinide ferromagnet [1], the understanding of fundamental properties have been lagging due to the nasty pyrophoric nature. Interesting aspects of electronic properties have been revealed during past few years, which was enabled by research of alloyed UH3 [2,3]. In particular, the metastable form, a-UH3, could be stabilized by Zr alloying, and it was found that basic magnetic features as Tc and ms are very similar to theb-UH3, despite different crystal structures and U-U distances [4]. The role of the transition elements in bonding and magnetism in the development of the two structures and their magnetism is still an open question. In my presentation, I am going to report results of the study of ultrafast-cooled U-Nb and U-Ti alloys and in particular of their hydrides. Characterization of the microstructure and crystal structure was performed by means of X-ray diffraction and advanced electron microscopy techniques (EBSD, EDX). Thermodynamic and transport properties of the materials were studied for a better understanding of the magnetic properties. One specific issue of the U-Ti hydrides is the known existence of the Laves phase UTi2Hx which forms exclusively with hydrogen only [5]. We could prepare it as bulk monolithic hydride, which allowed a thorough study of magnetic, transport, and thermodynamic properties [6]. We show how the U magnetism is tuned by variable H concentration in the range 5-6 H atoms/f.u., which allows to cross the onset of magnetic order. UTi2H6 is ferromagnet with TC = 55 K.

References:

[1] R. Troc, W. Suski, J. Alloys Compd. 219 (1995) 1–5.
[2] J. Prchal et al., J. Magn. Magn. Mater. 497 (2020) 165993.
[3] L. Havela et al., J. Electron Spectros. Relat. Phenomena. 239 (2020) 146904.
[4] I. Tkach et al., Phys. Rev. B. 91 (2015) 115116.
[5] T. Yamamoto et al., J. Nucl. Mater. 170 (1990) 140–146.
[6] V. Buturlim et al., Philos. Mag. 99 (2019) 1881–1898.