Amanda R. Krause's research while affiliated with Carnegie Mellon University and other places

... Under the influence of temperature, atoms can diffuse along the boundaries between particular crystallites, which leads to their coalescence. Moreover, annealing of polycrystalline films can lead to grain boundary migration to reduce the surface energy of the system [52]. Both of these mechanisms contribute to an increase in grain size with each successive repetition of the HT+RTA cycle. ...

... In another study, Khurjekar et al. (2023) examined the applicability of DL methods for classifying microstructures in materials science. Experiments conducted on the microstructure data of alumina monoliths obtained through EBSD were used to test the classification success of the DL algorithms. ...

... These experiments have yielded groundbreaking results concerning grain boundary velocities, mobilities and driving forces for migration. 49,[72][73][74] This method is still rapidly developing; at the time of writing, the approach boasts outstanding angular resolution (< 0.1°) with only limited spatial resolution ( ‡ 1 lm), requires access to a synchrotron radiation source and employs solely reciprocal space information for microstructural reconstruction. 73 HEXRD of data is still therefore relatively expensive to collect and process and is still relatively coarse in time and space compared to what is now possible in S/TEM instruments present at many institutions. ...

... However, extending reduced-order models-developed for isotropic systems-to anisotropic grain growth requires a careful investigation of the role of GB anisotropy on the evolution of microstructure statistics, which is the primary objective of this paper. Decoupling the effects of GB energy anisotropy and mobility anisotropy on microstructure evolution from experimental data is non-trivial [32]. Therefore, we rely on computer simulations enabled by recent advances in threshold dynamics (TD) method [33]. ...

... The initial structure contains approximately 50 000 grains. We find that the grain size and number of sides distributions calculated from the GNN predictions (figures 4(b) and (c)) agree very well with results from phase-field simulations reported in literature [42,50,51]. Nevertheless, the computation cost of GNN is substantially lower than phase-field simulations, which will be compared in a later section. ...

... For example, the observation of cryogenic and thermally damped GB migration (14) and antithermal GB migration (15) cannot be explained by Equation 2. It has recently been pointed out that Equation 2 applies only in the condition that H a κγ , and when the barrier is small compared with the driving force, both cryogenic and thermally damped GB migration are possible (16). Recent experimental (17)(18)(19) and computational (11,(20)(21)(22) studies also draw into question the validity of Equation 1, which does not agree with observations in polycrystals. In summary, while the simple model depicted by Equations 1 and 2 is consistent with observations of bicrystals and some average behavior of polycrystals, it has not been successful in describing the motion of individual boundaries in polycrystals. ...

... The analysis of ceramics by Raman spectroscopy offers interesting characterisation perspectives for mechanics [13,17,18] and tribology [16,19,20]. The spectrometer laser can reach micrometres or even sub-micrometre probe sizes when focused on a sample using a microscope. ...

... Grain boundary (GB) chemistry and structure have been demonstrated to play a crucial role in determining microstructural and mechanical properties of magnesium aluminate spinel (MAS, MgAl 2 O 4 ) [1,2]. For this reason, it is of great interest to corroborate the presence of dopant atoms at GBs to gain a better understanding of the relationship between segregation behavior and bulk properties. ...

... Instead, an ordered GB structure termed domino was found [14][15][16][17]. In Cu, an additional pearl structure occurs [14,15,17], meaning two GB phases [18][19][20][21][22] exist and can transition into one another based on the thermodynamic conditions [14,15,17]. On the second symmetric plane, inclined by 30 • , only a single GB phase (termed zipper) was reported for 19b [111] {235} and 37c [111] {347} GBs [16,23,24]. ...

... However, evidence of abnormal grain growth was found as a consequence of the Ca addition. A similar abnormal grain-growth behavior was reported in Eu-doped spinel materials where Eu atoms preferentially segregate on the grain boundaries inducing abnormal grain growth [5,6]. Fig. 2 (b) shows that, after hot-pressing, the microhardness values were lower in the pure spinel sample compared to the Ca-doped sample. ...