Ideally, every possible crystalline orientation is represented equally in a powdered sample. This “stripe”-like modulation is very similar to that in CePd 5Al 2 with q=(0.235,0.235,0)q=(0.235,0.235,0) with the Ce moment parallel to the c-axis. Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl6 and other alloys are twinned. Abstract Research on low-dimensional materials has increased drastically in the last decade, with the discovery of two-dimensional transition metal carbides and nitrides (MXenes) produced by atom-selective chemical etching of laminated parent M n+1AXn (MAX) phases. Powder diffraction is a scientific technique using X-Ray or neutron diffraction on powder or microcrystalline samples for structural characterization of materials. The main focus of the chapter will be on diffraction methods that at present account for a small number of structural studies compared to those determined by single crystal X-ray diffraction, namely single crystal neutron diffraction, X-ray and neutron powder diffraction, and charge density methods. We also found a collinear magnetic structure with a Nd moment of 2.7(3) μB at 0.5 K parallel to the c-axis, where the ferromagnetically ordered a-planes stack with a four-Nd-layer period having a ++- sequence along the a-direction with the distance between adjacent Nd layers equal to a/2 (magnetic space group P anma). Here, we observed the magnetic reflections with the modulation vector q=(1/2,0,0)q=(1/2,0,0) below the ordering temperature T N. The magnetic structure of NdPd 5Al 2 has been studied by neutron powder diffraction. The successful agreement between neutron powder diffraction data and AIRSS suggests that this combined approach has excellent potential for the study of other (trans)uranium materials in which hydrogen bonding plays a key role in phase stability.
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