An Interactive Simulation and Visualization Tool for Conventional and Aberration-Corrected Transmission Electron Microscopy

Contrast transfer function (CTF) is a vital function in transmission electron microscopy (TEM). It expresses to what extent amplitudes converted from the phase changes of the diffracted waves contribute to the TEM image, including the effects of lens aberrations. Simulation is very helpful to understand the application of the function thoroughly. In this work, we develop the CTFscope as a component in the Landyne software suite, to calculate the CTF with temporal and spatial dumping envelopes for conventional TEM and to extend it to various aberrations (up to fifth order) for aberration-corrected (AC)- TEM. It also includes effects on the CTF and imaging due to the objective aperture and image drift for tutorial purposes. The CTFscope has a user-friendly graphical interface for simulation, visualization, saving, and loading of the microscopy conditions and results. It can be used to explore instrumental performance information due to optical aberrations, effects on the resolution of a TEM and AC-TEM, and for teaching electron microscopy courses

SPICA: stereographic projection for interactive crystallographic analysis

In numerous research fields, especially the applications of electron and X-ray diffraction, stereographic projection represents a powerful tool for researchers. SPICA is a new computer program for stereographic projection in interactive crystallographic analysis, which inherits features from the previous JECP/SP and includes more functions for extensive crystallographic analysis. SPICA provides fully interactive options for users to plot stereograms of crystal directions and crystal planes, traces, and Kikuchi maps for an arbitrary crystal structure; it can be used to explore the orientation relationships between two crystalline phases with a composite stereogram; it is also used to predict the tilt angles of transmission electron microscopy double-tilt and rotation holders in electron diffraction experiments. In addition, various modules are provided for essential crystallographic calculations

SPICA: stereographic projection for interactive crystallographic analysis

In numerous research fields, especially the applications of electron and X-ray diffraction, stereographic projection represents a powerful tool for researchers. SPICA is a new computer program for stereographic projection in interactive crystallographic analysis, which inherits features from the previous JECP/SP and includes more functions for extensive crystallographic analysis. SPICA provides fully interactive options for users to plot stereograms of crystal directions and crystal planes, traces, and Kikuchi maps for an arbitrary crystal structure; it can be used to explore the orientation relationships between two crystalline phases with a composite stereogram; it is also used to predict the tilt angles of transmission electron microscopy double-tilt and rotation holders in electron diffraction experiments. In addition, various modules are provided for essential crystallographic calculations

Effect of Sm content on energy product of rapidly quenched and oriented SmCo5 ribbons

The Sm-content dependence of phase composition, anisotropy, and other magnetic properties of Sm1+δCo5 (δ ≤ 0.12) ribbons melt spun at 10 m/s has been studied. The samples consist of hexagonal SmCo5 grains whose c axes are preferentially aligned along the long direction of the ribbon. The lattice parameter a and the cell volume (V) increase with increasing Sm content δ, whereas c decreases. Sm addition appears to improve the degree of the preferred orientation of the c-axis and to increase the mean grain size, which weakens the effective intergranular exchange coupling. Therefore, the remanence ratio, coercivity, and squareness of the hysteresis loops are significantly enhanced. The remanence ratio of 0.91 and the maximum energy product of 21.2 MGOe, which is the highest value reported so far for Sm–Co ribbons, are achieved for δ = 0.06. High performance in combination with simple processing may facilitate high-temperature applications for anisotropic Sm1+δCo5 ribbons

Effect of Sm content on energy product of rapidly quenched and oriented SmCo5 ribbons

The Sm-content dependence of phase composition, anisotropy, and other magnetic properties of Sm1+δCo5 (δ ≤ 0.12) ribbons melt spun at 10 m/s has been studied. The samples consist of hexagonal SmCo5 grains whose c axes are preferentially aligned along the long direction of the ribbon. The lattice parameter a and the cell volume (V) increase with increasing Sm content δ, whereas c decreases. Sm addition appears to improve the degree of the preferred orientation of the c-axis and to increase the mean grain size, which weakens the effective intergranular exchange coupling. Therefore, the remanence ratio, coercivity, and squareness of the hysteresis loops are significantly enhanced. The remanence ratio of 0.91 and the maximum energy product of 21.2 MGOe, which is the highest value reported so far for Sm–Co ribbons, are achieved for δ = 0.06. High performance in combination with simple processing may facilitate high-temperature applications for anisotropic Sm1+δCo5 ribbons

IGC Fabrication and TEM Characterization of Mn Nanoparticles

The reason for the enormous interest in nanomaterials is because they display unique and superior properties that are generally unavailable in conventional macroscopic materials. Gleiter and coworkers [1] first generated a novel solid structure with gas-like disorder, in addition to long-range order (crystalline and quasicrystalline solids) and short-range order (amorphous/glassy solids). Inert-gas condensation (IGC) is a well established nanoparticle production technique [2-4]. Figure 1 shows an IGC system equipped with magnetron sputter source and mass selector that was used in the present work. The ability to control the process parameters to fabricate metal nanoparticles with tailored size, shape, and properties is important for research in this area

New type of Al-based decagonal quasicrystal in Al\u3csub\u3e60\u3c/sub\u3eCr\u3csub\u3e20\u3c/sub\u3eFe\u3csub\u3e10\u3c/sub\u3eSi\u3csub\u3e10\u3c/sub\u3e alloy

A new kind of decagonal quasicrystal (DQC) with a periodicity of 1.23 nm was observed in the as-cast quaternary Al60Cr20Fe10Si10 alloy. The intensity distribution of some spots in the selected-area electron diffraction pattern along the tenfold zone axis was found to be different from other Al-based DQCs. High-angle annular dark-field scanning transmission electron microscopy was adopted to reveal the structural features at an atomic level. Both the tenfold symmetry and symmetry-broken decagonal (D) clusters of 1.91 nm in diameter were found, but with structural characteristics different from the corresponding D clusters in the other Al-based DQCs. The neighboring D clusters are connected by sharing one edge rather than covering, suggesting the tiling model is better than the covering model for structural description

A TEM study of Fe\u3csub\u3e3+x\u3c/sub\u3e Co\u3csub\u3e3-x\u3c/sub\u3eTi\u3csub\u3e2\u3c/sub\u3e (x = 0, 1, 2, 3) intermetallic alloys

A TEM study has been carried out on crystal structures in the rare-earth-free intermetallic alloys, Fe3+xCo3-xTi2 (x = 0, 1, 2, 3). These alloys have been demonstrated to have potentially high magnetic anisotropy. In these alloys, the main intermetallic compound was recently reported as a new hexagonal phase with a space group of P-6 m2. The present study reveals that the main compound belongs to Laves C14 variant surrounded by α-Fe type crystal as secondary phase in the Fe3+xCo3-xTi2 (x = 0, 1, 2, 3) alloys, in agreement with the Fe-Ti and Fe-Co-Ti phase diagrams. The SAED, EDS, HRTEM and XRD techniques have been carried out to characterize the intermetallic compounds in the Fe3+xCo3-xTi2 (x = 0, 1, 2, 3) alloys

A modulated structure derived from the XA-type Mn\u3csub\u3e2\u3c/sub\u3eRuSn Heusler compound

A modulated structure derived from the inverse Heusler phase (the XA-type and the disordered variant L21B-type) has been observed in rapidly quenched Mn2RuSn ribbons. The powder X-ray diffraction pattern of the quenched ribbons can be indexed as an L21B-type structure. Electron diffraction patterns of the new structure mostly resemble those of the XA-type (and the disordered variant L21B-type) structure and additional reflections with denser spacing indicate a long periodicity. Orthogonal domains of the modulated structure were revealed by a selected-area electron diffraction pattern and the corresponding dark-field transmission electron microscopy images. The structure was further studied by the crystallographic analysis of high-resolution transmission electron microscopy images. A model for the modulated structure has been proposed to interpret the experimental results