12310-44-0Relevant academic research and scientific papers
The properties of lattice, electronic and magnetic subsystems of erbium tetraboride based on calorimetric data at temperatures of 2-300 K
Novikov,Morozov,Matovnikov,Mitroshenkov,Avdashchenko,Kuznetsov,Kornev,Marakhina,Novikov,Bordacheva
, p. 431 - 434 (2013)
The temperature dependence of heat capacity Cp(T) of an erbium tetraboride sample, synthesised by the borothermal reduction of metal from oxide in a vacuum, is researched by the absolute adiabatic calorimetry method. The transition of the tetraboride into an antiferromagnetic state at TN = 15.1 K is revealed on the Cp(T) curve by a sharp maximum. The values of ErB4 heat capacity are presented as the sum of electronic C e(T), magnetic Cm(T), and lattice Clat(T) components, as well as Schottky contribution CSch(T). The characteristics of these components are defined: the electronic heat capacity coefficient, parameter of interaction in the magnetic subsystem, entropy and enthalpy of magnetic transformation, splitting scheme of Er3+ ion level, and the residual entropy of the magnetic subsystem at absolute zero, conditioned by the lattice frustration of erbium tetraboride.
Mechanochemical synthesis of erbium borohydride: Polymorphism, thermal decomposition and hydrogen storage
Gennari
, p. 192 - 195 (2013)
A new erbium borohydride Er(BH4)3 was synthesized from 3LiBH4 and ErCl3 through mechanochemical processing. This rare-earth metal borohydride presents a primitive cubic structure with a = 10.74(1) A, which is isostructural with the one previously reported for R(BH4)3 (R = Y, Dy and Gd). During heating Er(BH4)3 exhibits a reversible structural transformation at about 220 °C, analogous to that observed for Y(BH4)3. Combination of thermal hydrogen desorption, DSC, XRPD and FTIR measurements allows to determine that thermal decomposition of Er(BH4)3 starts at 230 °C and leads to 3.2 wt% of hydrogen release obtaining ErH2, an unknown intermediate compound and ErB4. It was observed that Er(BH 4)3 is partially reversible under 6.0 MPa of H2 at 400 °C and absorbs about 20% of the total hydrogen capacity obtained experimentally.
Flux synthesis, crystal structure and electronic properties of the layered rare earth metal boride silicide Er3Si5-xB. An example of a boron/silicon-ordered structure derived from the AlB2structure type
Babizhetskyy, Volodymyr,Jardin, Régis,Gautier, Régis,Fontaine, Bruno,Halet, Jean-Fran?ois
, p. 869 - 879 (2021/10/25)
The ternary rare earth metal boride silicide Er3Si5-x B (x = 1.17) was synthesized from the elements using the tin flux method. It crystallizes in a new structure type in the space group R32 (a = 6.5568(1) ?, c = 24.5541(1) ?, Z = 6). The structural arrangement can be derived from the AlB2 structure type with boron/silicon ordering in the layered metalloid substructure made of [Si5B] hexagons. The presence or absence of the boron atoms involved in this ordered structure is discussed on the basis of difference Fourier syntheses and structural analysis, in relation with the binary parent structures AlB2 and Yb3Si5 (Th3Pd5 type). The electronic and bonding properties of Er3Si5-x B were analyzed and discussed via density functional theory (DFT) calculations and a crystal orbital Hamiltonian population (COHP) bonding analysis.
The ternary RE-Si-B systems (RE = Dy, Ho, Er and Y) at 1270 K: Solid state phase equilibria and magnetic properties of the solid solution REB2-xSix (RE = Dy and Ho)
Roger, Jérome,Babizhetskyy, Volodymyr,Guizouarn, Thierry,Hiebl, Kurt,Guérin, Roland,Halet, Jean-Fran?ois
, p. 72 - 84 (2008/10/09)
The solid state phase equilibria in the ternary RE-Si-B diagrams (RE = Dy, Ho, Er and Y) were determined at 1270 K using experimental techniques such as X-ray diffraction, scanning electron microscopy and electron probe microanalysis. In general, three ternary phases were obtained for each diagram: the line compound RE5Si2B8 with tetragonal symmetry, the boron-inserted Nowotny phase RE5Si3Bx of Mn5Si3-type and the solid solution REB2-xSix of AlB2-type. Prior to this work, the binary systems RE-Si and RE-B, which form the boundary of each diagram, were also re-investigated. In addition to the structures of RE5Si3 (Mn5Si3-type, RE = Dy, Ho and Y) and Dy3Si4 (Ho3Si4-type) which were previously reported or will be presented in a forthcoming paper, the X-ray single crystal structures of RE5Si4 (Sm5Ge4-type, RE = Dy and Ho), DySi (CrB-type) and HoSi in both polymorphic modifications, i.e. the FeB- (high temperature) and CrB- (low temperature) types, were determined and are described herein. Structural relationships between members of the same series on one side, and between both forms of HoSi on the other side, are also discussed in terms of coordination polyhedra and interatomic distances. Finally, magnetic measurements were performed on the alloys REB2-xSix, which in case of RE = Dy exhibit a marked increase of the magneto-crystalline anisotropy, whereas for RE = Ho a change from ferromagnetic to antiferromagnetic behaviour with increasing silicon content is encountered.
