A simple method for the analysis of dislocation loops by means of the inside-outside contrast on transmission electron micrographs

Abstract

A new method is proposed for the analysis (vacancy or interstital) of dislocation loops by means of the so‐called inside‐outside contrast. A simple and straightforward recipe is developed which is applicable in the same manner to loops of edge and of non‐edge type irrespective of the loop orientation within the transmission foil; in particular, there is no reason for a subdivision of the loop orientations into “safe” and “unsafe” orientations as required when applying the method of Maher and Eyre.

Microstructural Investigations of Barium Titanate‐Based Material for Base Metal Electrode Ceramic Multilayer Capacitor

“…5. Consequently, further thorough determination of the character type 15 is not feasible. In all cases, no chemical difference before and after beam-induced loop removal is detected.…”

Dislocation Loops in Pressureless‐Sintered Undoped BaTiO3 Ceramics

“…Dislocation loops (shown in Fig. 2) revealed by a “black‐dot” contrast, 1,2,14–16,22 representing a center of small strains, 12–18,22 were associated with the ferroelectric domains, 22,24 decorating the domain walls, 1 where the 90° domains were viewed edge on. The loops varied in sizes between ∼10 and 30 nm.…”

“…The nature of loops was characterized sequentially by three steps 13–18 (1) using the g·b =0 invisibility criteria combined with (2) the inside–outside contrast technique using ( g·b ) s g <0 or >0 while keeping the excitation error s g >0 to determine both the direction and sense of the Burgers vector ( b ), and (3) tilting the loops to an edge‐on orientation or observing changes in the projected direction of the loop major axis upon tilting about a particular g vector to evaluate the loop plane normal ( n ).…”

“…In contrast to the crystallographic shear (CS) structure and unstable loops reported 1 for acceptor‐doped compositions sintered in reducing atmospheres, we have observed in undoped BaTiO 3 ceramics, prepared by pressureless sintering of TiO 2 excess powder, ubiquitous dislocation loops that have survived irradiation by an electron beam at 300 keV. Such loops are characterized for the Burgers vectors ( b ), the habit plane normal ( n ), and its nature of vacancy or interstitial by the g·b =0 (effective) invisibility criteria, and the inside–outside contrast technique, 13–18 together with high‐resolution imaging, 1,4 are reported here. Atomic models that probably represent the dislocation loops are proposed.…”

Nature of dislocation loops in electron-irradiated CuAuI and Cu3Au

“…The six kinds of loops with n/2( 11 0) Burgers vectors are classified into the two types : the loops A, B, C and D lying on planes close to (010) and (100) Determination of the interstitial or vacancy nature can be made by the Foll and Wilkens method (Foll and Wilkens 1975) which is applicable for non-edge loops . Figures 3 ( a ) and ( b ) show inside and outside contrast of the loops B with g = 111 and 111 under s > 0 near [ O l l ] .…”