Crystal structure of ErFe2D3.1 and ErFe2H3.1 at 450K

Magnetic transitions with magnetocaloric effects near room temperature related to structural transitions in Y0.9Pr0.1Fe2D3.5 deuteride

“…However, the intensity of several cubic peaks was not very well fitted, in particular those with (hhh) Miller indices, and few peaks (Q =1.59, 3.55, 7.93 Å -1 ) were not indexed. This suggests a lowering of crystal symmetry and we have tested two different subgroups (R-3m and F23 SG) according to previous publications on YFe2D3.5 and ErFe2D3.1 [22,53]. All additional peaks can be indexed with both space groups.…”

Structural and magnetic properties of ErFe2D3.1

“…The ErFe 2 D 3.1 sample preparation is described elsewhere [16]. Neutron powder diffraction patterns have been measured on the HRPT diffractometer at the SINQ facility, Paul Scherrer Institute (Villigen, Switzerland) with the neutron wavelength of k = 1.494 Å.…”

“…2a at 450 K the compound exhibits a single-phase cubic structure (a). According to our previous work [16] the crystal structure of ErFe 2 D 3.1 at 450 K can be described with the F23 space group (SG) which is a subgroup of Fd3m SG usually applied for the parent RFe 2 compounds and their hydrides (see Fig. 3a).…”

“…Moreover, according to our neutron diffraction data the cubic-to-orthorhombic phase transition occurs at about 400 K which is above the Curie temperature T C = 380 K. Thus we can conclude that the structure distortions of ErFe 2 D 3.1 cannot be attributed to magnetostriction properties. In our previous work [16] a random distribution of deuterium atoms over 96 A 2 B 2 interstitial sites with occupation factor about 28% has been obtained from Rietveld refinement of the ErFe 2 D 3.1 NPD pattern at T = 450 K. It can be considered as a solid solution of deuterium in the cubic structure. In the present study a careful analysis of the ErFe 2 D 3.1 structure on cooling down to 12 K revealed a coexistence of the cubic deuterium-deficient (x < 3.2 at/f.u.)…”

“…In the vicinity of this critical composition the temperature-induced structural transition at fixed hydrogen content can be observed. In our previous paper [16] we have studied the crystal structure of ErFe 2 D 3.1 and ErFe 2 H 3.1 at the high temperature of 450 K in the paramagnetic state. The present paper is the next step for understanding the hydrogen influence on the crystal structure and magnetic properties of the ErFe 2 .…”