Impurity segregation at alloy grain boundaries (GB) depends on many parameters such as GB character and prior thermomechanical history. In this paper we describe an experimental set-up designed to record the individual behaviour of GB during recrystallization of a Nickel-Sulphur alloy. The aim is to correlate segregation level with mobility and disorientation of GB. Therefore a method allowing direct observation of the GB motion as well as disorientation mapping is needed.

Studying grain growth and recrystallization of this particular alloy by Scanning Electron Microscopy is possible thanks to real time in-situ imaging. This requires a sensitive crystal orientation contrast and the ability to image hot evolving samples. To heat the samples, a special device designed for the SEM analysis chamber is used. This device is used at 455°C but is able to reach higher temperatures. In order to get the orientation contrast images, as well as to protect the Secondary Electron (SE) detector from heat and light, a channel plate converter has been designed. This experimental set-up, combined with the heating system, allow the observation of the sample during recrystallization and recording small videos providing information such as grain boundary displacement rate. Then, associated with an EBSD analysis we can get the disorientation map of the area of interest and eventually an electrochemical technique is performed to create preferential dissolution at GB. Geometry of the grooves resulting from an electrochemical etching gives an evaluation of the segregation level in GB.

Cu interconnects have decreased in width and are at around 100 nm. A decrease in interconnect width have led to a predominately bamboo structured Cu lines. In Cu interconnects, void formation during high temperature is a reliability issue, and this study looks at the void formation behavior in damascene Cu interconnects with a predominately bamboo microstructure. First, the crystal texture and grain morphology of the Cu interconnects was observed. Then to determine the void formation behavior, in-situ Transmission Electron Microscopy (TEM) was performed. Voids that formed as a result of in-situ heating were analyzed in terms of preferential void formation sites and crystal orientation where voids formed. In bamboo structured lines, voids formed at the triple junction of grain boundary and Cu/diffusion barrier interface. The crystal orientation where voids nucleated was studied to identify diffusion paths during void nucleation and growth.

In this contribution an in-situ TEM experiment is suggested to observe the microstructure of a metal/oxide insulator/metal (MIM) capacitor structure during resistive switching due to an applied external voltage or current. The motivation for such an experiment is the fact that there is a large pool on the resistive switching data in the literature, but there is no agreement on the mechanism, which in part is due to missing microstructural observations of the effects. For such an experiment a special TEM sample holder has been developed allowing controlled in-situ application of temperature (RT to 300°C) with a heating stage and of voltage (current) as a part of a 4-terminal resistance measurement set-up. This is combined with a special TEM sample preparation method, the “window”-technique, so that no thinning of the MIM thin film structure is necessary at all (which is an advantage as the oxides are known to be very sensitive to damage introduced by methods such as ion-milling). Special electrode configurations have been designed to allow nearly undisturbed TEM observation of the switching insulator. Identical samples will also be investigated ex-situ in conventional switching experiments to identify the influence of the special TEM environment (high vacuum, irradiation with energetic electrons).

Electromagnetic fields presents in some real materials have been observed using electron holography and a simple method named the Shadow Image Distortion (SID) method which we have developed. The in-situ electron holography observation of the electric field surrounding a ceramic particle showed the rapid degradation of dielectric properties of the particle at an elevated temperature. The cross sectional view of mean electrostatic potential distributions in a silicon device has been observed. In-situ electron holography and SID observations showed the electrostatic potential distribution across a reverse biased p-n junction in a compound semiconductor. The SID method using a dedicated tool allowed single-step imaging of 2D maps of electromagnetic field.

We have measured the transient events of the α-β martensitic transformation in nanocrystalline Ti films via single shot electron diffraction patterns with 1.5 ns temporal resolution. This was accomplished with a newly constructed dynamic transmission electron microscope (DTEM), which combines pulsed laser systems and pump-probe techniques with a conventional TEM. The DTEM thereby enables studies of transformations that are (1) far too fast to be captured by conventional bulk techniques, and (2) difficult to study with current ultrafast electron diffraction (UED) instruments (which typically require an accumulation of multiple shots for each diffraction pattern). Martensitic transformations in nanocrystalline materials meet both criteria, with their rapid nucleation, characteristic interface velocities ∼1 km/s, and significant irreversible microstructural changes. Free-standing 40-nm-thick Ti films were laser-heated at a rate of ∼1010 K/s to a temperature above the 1155 K transition point, then probed at various time intervals with a 1.5-ns-long intense electron pulse. Diffraction patterns show an almost complete transition to the β phase within 500 ns. Post-mortem analysis (after the sample is allowed to cool) shows a reversion to the α phase coupled with substantial grain growth, lath formation, and texture modification. The cooled material also shows a complete lack of apparent dislocations, suggesting the possible importance of a "massive" short-range diffusion mechanism.

Electromigration (EM) in unpassivated copper lines at room temperature has been investigated in ultra-high vacuum by in-situ transmission electron microscopy (TEM). The electric current induced atomic migration in a (211)-oriented Cu grain has been successfully recorded in real-time video. The atomic image of the (211) grain was found to vanish directionally when applying an electric current density of 2 × 106 A/cm2 through the Cu line. The results suggested that the combination of {111} planes and <110> directions to be the easiest EM path in crystalline copper. By performing selective area diffraction (SAD) analysis on a single Cu grain with (111) crystal orientation, some unusual electron diffraction patterns appeared after passing an electric current through the Cu line. It is believed that the EM-induced Cu twinning may be held responsible for the unique diffraction patterns

The deformation and failure processes in ultra-fine and nanograined metals over different length scales have been probed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) in combination with a micromechanical in situ straining device. This novel straining device affords the opportunity to directly correlate the macroscopic mechanical properties with the microscopic deformation and failure mechanisms. Through use of this device it has been shown that increased film thickness results in a transition between limited plasticity and intergranular fracture to global plasticity and shear failure for deposited aluminum samples of similar grain size but different thickness.

In situ transmission electron microscopy was used to show that nanocrystalline nickel produced by pulsed-laser deposition undergoes abnormal grain growth at moderate temperatures (225-400°C). The growth rate was found to increase with thickness for the three film thicknesses examined, 50, 80 and 150 nm. The abnormal growth proceeded in an irregular manner: initiation sites and growth direction were unpredictable, and the grains exhibited no preferred orientation. Some abnormal grains show internal boundaries such as twins, while others exhibited lattice misalignments across the grain body. The grains contain many defects, including dislocations, stacking faults and surprisingly, stacking fault tetrahedra. The stacking fault tetrahedra are not a result of quenching nor of electron irradiation-induced lattice displacements; they instead are thought to form from vacancies trapped in the growing grain as it incorporates lower-density material at the high-angle grain boundaries in the nanocrystalline matrix.

Retention of the enhanced properties reported for nanograined metallic systems requires that the nanostructure be insensitive to temperature and deformation. In situ transmission electron microscopy annealing experiments were employed to investigate the structural changes associated with the formation of micron-sized grains in nanograined evaporated gold thin films. This abnormal grain growth occurs randomly throughout the film. Twinning but not dislocation slip occurs in the growing grains until the grain size is in the hundreds of nanometer range. The twins appear to hinder growth and for grain growth to continue the twins must either be annihilated or be able to grow with the grain concurrently.

The processes of phase transformation in individual nanoparticles of FePt and FePtCu synthesized by the reverse micelle method, which are chemically homogeneous and monodisperse, have been investigated by an in-situ HREM observation in a FE-TEM. Polycrystalline FePt particles, initially of chemically disordered face-centered cubic phase (A1) were reconstructed into A1 single crystals between 25 °C and 650 °C, followed by phase transformation from A1 to chemically ordered face-centered tetragonal phase (L10) which began between 650 °C and 680 °C. The coalescence began concurrently with phase transformation, i. e., between 650 °C and 680 °C. They turned to be a round-shaped L10 particle between 680 °C and 720 °C. The single crystal formation, the phase transformation from A1 to L10, the coalescence and the round-shaped particle formation were also observed in the FePtCu nanoparticles. The temperatures of single crystal formation, phase transformation (and coalescence) and round-shaped particle formation of the FePtCu nanoparticles were between 25 °C and 500 °C, between 550 °C and 600 °C and between 600 °C and 650 °C, respectively. These temperatures were substantially lower than those for the FePt nanoparticles.

One of the most widely studied types of magnetic nanostructure is that used in devices based on the giant magnetoresistance (GMR) or tunnel magnetoresistance (TMR) phenomena. In order to understand the behaviour of these materials it is important to be able to follow their magnetisation reversal mechanism, and one of the techniques enabling micromagnetic studies at the sub-micron scale is transmission electron microscopy. Two techniques can be used: Lorentz transmission electron microscopy and off-axis electron holography, both of which allow the magnetic domain structure of a ferromagnetic material to be investigated dynamically in real-time with a resolution of a few nanometres. These techniques have been used in combination with in situ magnetizing experiments, to carry out qualitative and quantitative studies of magnetization reversal in a range of materials including spin-tunnel junctions, patterned thin film elements and magnetic antidot arrays. Quantitative analysis of the Lorentz TEM data has been carried out using the transport of intensity equation (TIE) approach.