A03 - Correlative structural, chemical and bonding characterisation of 1D and 2D defect phases

PI(s): Joachim Mayer (RWTH Aachen University, GFE), Alexander Schwedt (RWTH Aachen University, GFE)

SFB researchers: Marta Lipińska-Chwałek (Forschungszentrum Jülich, ER-C), Joshua Spille (RWTH Aachen University, GFE)

Engineering of advanced structural materials by incorporation of low-dimensional microstructural elements or defect phases, which is the main aim of the CRC 1394, can only be reached if a full characterisation of these property-controlling components can be accomplished down to the atomic-level.

In the present project, a correlative approach ranging from scanning electron microscopy (SEM) to aberration-corrected high resolution (scanning) transmission electron microscopy (HR(S)TEM) as well as atom probe tomography (APT) will be applied to elucidate the structure-property relationships of defect phases as well as their chemical compositions (cf. Fig. 1).

The materials provided by projects S, A01, A05, B02, C02, C03 and C04 are investigated in project A03 with respect to the structural and chemical properties of the structural defects. These defects range from 0D defects, like impurity atoms and small ordered clusters, via 1D defect phases, i.e. dislocations in the bulk and at interfaces, up to planar 2D defect phases like stacking faults and grain boundaries, including special boundaries as twin boundaries. The high resolution results are handed over to project A04 for further processing, while structural and analytical data is shared with projects A01, A02, A05, A06, A07, B01, B03, B06, B08, C02, C04 and C05 for comparison and as input for the modelling and simulation activities.

Sample preparation, SEM investigations and conventional TEM analyses are performed at the Central Facility for Electron Microscopy (GFE) of RWTH Aachen University, while advanced (S)TEM measurements are conducted at the Ernst Ruska-Centre (ER-C), which is one of the leading infrastructures in terms of aberration-corrected TEM operated jointly by RWTH Aachen University and Forschungszentrum Jülich.