Abstract The process of ordering with phase separation and domain structure of Fe-Al and Fe-Ga alloys in the regions of mixed phases A2 + B2 and A2 + DO3 have been investigated by transmission electron microscopy. Observation by dark field micrographs with superlattice reflections revealed a complicated process of phase separation strongly depending on alloy composition and temperature, which was in good agreement with thermodynamics based on Landau's phenomenological theory. Key Words: phase separationorderingdomain structurespinodal decompositionFe-AlFe-Ga
ABSTRACT We present the overview and first results from the North-PHASE Legacy Survey, which follows six young clusters for five years, using the 2 deg$^2$ FoV of the JAST80 telescope from the Javalambre Observatory (Spain). North-PHASE investigates stellar variability on time-scales from days to years for thousands of young stars distributed over entire clusters. This allows us to find new YSO, characterize accretion, and study inner disc evolution within the cluster context. Each region (Tr 37, Cep OB3, IC 5070, IC 348, NGC 2264, and NGC 1333) is observed in six filters (SDSS griz, u band, and J0660, which covers H$\alpha$), detecting cluster members as well as field variable stars. Tr 37 is used to prove feasibility and optimize the variability analysis techniques. In Tr 37, variability reveals 50 new YSO, most of them proper motion outliers. North-PHASE independently confirms the youth of astrometric members, efficiently distinguishes accreting and non-accreting stars, reveals the extent of the cluster populations along Tr37/IC 1396 bright rims, and detects variability resulting from rotation, dips, and irregular bursts. The proper motion outliers unveil a more complex star formation history than inferred from Gaia alone, and variability highlights previously hidden proper motion deviations in the surrounding clouds. We also find that non-YSO variables identified by North-PHASE cover a different variability parameter space and include long-period variables, eclipsing binaries, RR Lyr, and $\delta$ Scuti stars. These early results also emphasize the power of variability to complete the picture of star formation where it is missed by astrometry.
The sink strengths of precipitate/matrix interfaces in Cu alloys, were investigated by performing in-situ observation of electron irradiation in high-voltage electron microscopy (HVEM). Fine black spot defects, which seemed to be dislocation loops were observed at irradiation temperature ranging between RT and 373 K in Cu–Cr–Zr, Cu–Cr and GlidCop Al–60 alloys with low number density. In Cu–Cr, loops formed on a part of precipitates interfaces. Hence, a part of precipitate/matrix interfaces is a sink with interstitial bias. Whereas, most of the interfaces are neutral sinks for point defects. In the case of Cu–Cr–Zr and GlidCop Al–60, black spots formed around dislocation, which were induced during two-step heat treatment. The results showed that the precipitate/matrix interface of Cr-rich precipitates in Cu alloys serve as a strong sink for point defects.