Skip to Main content Skip to Navigation
Theses

Contribution à l'étude des propriétés structurales et magnétiques de composés intermétalliques isotypes de CeScSi et Th6Mn23

Abstract : The structural and electronic properties study of the RMgSn and RMgPb (R = rare-earth) series allowed to show that the great stability of the CeScSi-type is related to strong T X and R-X bonds and to good structure adaptation to the size of the element R. These series represent the first two examples of CeScSi-type compounds with antiferromagnetic behaviors characterized by complex modulated magnetic structures. The new RTiGeBx (R = Y, Gd-Tm, Lu) compounds crystallize in the YTiGeCx-type structure, a partially carbon filled CeScSi-type. They exhibit ferromagnetic ordering at high temperature locally perturbed by the boron atoms. For the first time, neutron diffraction experiments evidenced an antiferromagnetic order of the chromium sublattice in the ThCr2Si2 compound, while UCr2Si2 exhibits only an antiferromagnetic ordering of the uranium sublattice. The new UCr2Si2C compound crystallizes in the CeCr2Si2C-type and presents, on the contrary of the other RCr2Si2C, an antiferromagnetic order of the chromium sublattice. The new RCr3Si2C (R = Y, Gd-Tm, Lu, U) compounds crystallize in the new YCr3Si2C-type structure with the space group P6/mmm and cell parameters a ~ 9 Å et c ~ 4 Å. Electronic structure calculations allowed to explain the structural stability. In the field of the magnetic refrigeration, the study of the R6Mn23 (R = Gd-Tm) compounds has been undertaken. These materials exhibit a moderate magnetocaloric effect over a broad temperature range. Many substitutions showed that these characteristics can be easily adjusted.
Document type :
Theses
Complete list of metadatas

Cited literature [69 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01746209
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 10:27:27 AM
Last modification on : Thursday, February 25, 2021 - 11:04:56 AM
Long-term archiving on: : Thursday, September 13, 2018 - 12:01:03 PM

File

SCD_T_2011_0077_LEMOINE.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01746209, version 1

Citation

Pierric Lemoine. Contribution à l'étude des propriétés structurales et magnétiques de composés intermétalliques isotypes de CeScSi et Th6Mn23. Autre. Université Henri Poincaré - Nancy 1, 2011. Français. ⟨NNT : 2011NAN10077⟩. ⟨tel-01746209⟩

Share

Metrics

Record views

50

Files downloads

534