Investigate the local structure of domain walls in polarisation superctrystals of KTN:Li. These could be responsible for the giant refraction observed in these systems.

This proposal aims to examine the crystal quality of heteroepitaxial selective area grown (SAG) PbTe on CdTe using molecular beam epitaxy. PbTe is a promising material for detecting Majorana bound states, which are essential for fault-tolerant quantum bits. However, high-quality, low disorder heteroepitaxy is required to achieve this. Scanning X-ray diffraction microscopy at the ID01 beamline will be employed to analyse strain and rotation distributions in PbTe samples. Our findings will address key aspects like mask constriction, crystal reorientation during growth, and lattice mosaicity on the quality of PbTe nanowire networks.

We have developed a novel method for nanopatterning ferrimagnetic thin films to locally tailor their magnetic properties, enabling the realization of functional magnonic nanodevices. The precise physical mechanism underlying the local modification of properties remains unclear. Preliminary evidence suggests that the appearance of strain following a laser-induced formation of oxygen vacancies may be involved. We propose to employ SXDM at ID01 to definitively determine the presence, extent, and spatial characteristics of this strain.

Non-centrosymmetric lacunar spinels like GaMo₄S₈ host an exotic, Jahn-Teller effect driven polar state lacking antiphase ferroelectric domains at low temperature. Our preliminary cryogenic transmission electron microscopy data suggest that these domains form a 2D polar supercrystal state in thin GaMo₄S₈ lamellae. Here, we propose an in-situ scanning X-ray diffraction microscopy (SXDM) study of GaMo₄S₈ lamellae as a function of temperature to investigate the emergence of periodic domain patterns. Using ID01 at ESRF, we aim to spatially resolve the local lattice distortions and domain tilts, providing direct evidence of this new supercrystal structure emerging in polar non-ferroelectric materials.