Neutron scattering structural study of AlCuFe quasicrystals using double isotopic substitution

Constraints on pure point diffraction on aperiodic point patterns of finite local complexity*

“…This brings up a question: are partial amplitudes a k experimentally measurable? Since formally a k can be derived (up to a common phase factor) through the dependence of the Bragg peak intensities (20) on the weights w p , one can think of using the method of isotopic substitution in neutron diffraction experiments [24]. However, this approach does not allow to distinguish the contributions of the same chemical element in different local environments.…”

Constraints on pure point diffraction on aperiodic point patterns of finite local complexity

“…This brings up a question: are partial amplitudes a k experimentally measurable? Since formally a k can be derived (up to a common phase factor) through the dependence of the Bragg peak intensities (20) on the weights w p , one can think of using the method of isotopic substitution in neutron diffraction experiments [21]. However, this approach does not allow to distinguish the contributions of the same chemical element in different local environments.…”

Structural transformation from the AlCuFe icosahedral phase to the 1/1 cubic (AlSi)CuFe approximant phase; three dimensional models of translation defects

“…A 3D model of the AlCuFe icosahedral structure has been obtained by irrational projection in parallel space (3D real space) of the nodes of a 6D hypercubic lattice [3,4,9]. It was determined from a 6D neutron diffraction study [10] that the AlCuFe icosahedral structure is defined in 6D space by 3 atomic surfaces located at the N [000000] and N [100000] nodes of a primitive lattice and at the BC 1/2[111111] body-centre; the other BC 1/2[111111] body-centre is vacant. The size and shape of the atomic surfaces, in perpendicular space, determine the occupation in real space of the nodes of the four sublattices: Figure 3 is a two-fold section of this 3D model, previously described by Le Lann and Devaud [5].…”