Interaction between Screw Dislocation and Interfacial Crack in Fine-Grained Piezoelectric Coatings under Steady-State Thermal Loading

The mechanical behavior of fine-grained piezoelectric/substrate structure with screw dislocation and interface edge crack under the coupling action of heat, force and electricity are studied. Using the mapping function method, firstly, the finite area plane is transformed into the right semi-infinite plane, then the expression of the temperature field is given with the help of the complex function, and then the temperature field of the problem is achieved. By constructing the general solution of the governing equation with temperature function, the analytical expression of the image force is derived. Finally, the effects of material parameters, temperature gradient, coating thickness and crack size on image force are analyzed by numerical examples. The results show that the temperature gradient has a very significant effect on the image force, and thicker coating is conducive to the stability of dislocation and interface crack.

Tool-Use Model to Reproduce the Goal Situations Considering Relationship Among Tools, Objects, Actions and Effects Using Multimodal Deep Neural Networks

We propose a tool-use model that enables a robot to act toward a provided goal. It is important to consider features of the four factors; tools, objects actions, and effects at the same time because they are related to each other and one factor can influence the others. The tool-use model is constructed with deep neural networks (DNNs) using multimodal sensorimotor data; image, force, and joint angle information. To allow the robot to learn tool-use, we collect training data by controlling the robot to perform various object operations using several tools with multiple actions that leads different effects. Then the tool-use model is thereby trained and learns sensorimotor coordination and acquires relationships among tools, objects, actions and effects in its latent space. We can give the robot a task goal by providing an image showing the target placement and orientation of the object. Using the goal image with the tool-use model, the robot detects the features of tools and objects, and determines how to act to reproduce the target effects automatically. Then the robot generates actions adjusting to the real time situations even though the tools and objects are unknown and more complicated than trained ones.

The lattice dislocation trapping mechanism at the ferrite/cementite interface in the Isaichev orientation relationship

We analyze the lattice dislocation trapping mechanism at the ferrite/cementite interface of the Isaichev orientation relationship by atomistic simulations combined with the anisotropic linear elasticity theory and disregistry analysis. We find that the lattice dislocation trapping ability is varied by initial position of the lattice dislocation. The lattice dislocation near the interface is attracted to the interface by the image force generated by the interface shear, while the lattice dislocation located far is either attracted to or repelled from the interface, or even oscillates around the introduced position, depending on the combination of the stress field induced by the misfit dislocation array and the image stress field induced by the lattice dislocation.

Modified expressions of field and thermionic-field emission for Schottky barrier diodes in the reverse regime

In this theoretical work, the author has modified the current-voltage relationship of the field and thermionic–field emission models developed by Padovani and Stratton for the Schottky barrier diodes in the reverse bias conditions with account of the image force correction. Considered in this approach has been the shape of Schottky barrier as trapezoidal. The obtained results show a good agreement between current densities calculated within the framework of these developed models and those calculated using the general model.

The Lattice Dislocation Trapping Mechanism at the Ferrite/Cementite Interface: The Isaichev Orientation Relationship

We analyze the lattice dislocation trapping mechanism at the ferrite/cementite interface (FCI) of the Isaichev orientation relationship (OR) by atomistic simulations combined with the anisotropic linear elasticity theory and disregistry analysis. We find that the lattice dislocation trapping ability is varied by initial position of the lattice dislocation. The lattice dislocation near the interface is attracted to the interface by the image force generated by the interface shear, while the lattice dislocation located far is either attracted to or repelled from the interface, or even oscillates around the introduced position, depending on the combination of the stress field induced by the misfit dislocation array and the image stress field induced by the lattice dislocation.

On the Examination of Temperature-Dependent Possible Current-Conduction Mechanisms of Au/(nanocarbon-PVP)/n-Si Schottky Barrier Diodes in Wide Range of Voltage

Au/(nanocarbon-PVP)/n-Si SDs were fabricated and their current-conduction mechanisms (CCMs) have been examined in elaborative by utilizing current-voltage (I-V) characteristics in temperature range of 60-340K at (± 3V) ranges. The values of ideality factor (n) and zero-bias barrier height (ΦBo) determined from the linear-part of semilogarithmic forward bias IF-VF properties based on Thermionic-Emission (TE) theory revealed that decrease in ΦBo and increase in n with deccreasing temperature. Additionally, Richardson constant (A*) value was found several orders lower than its theoretical value. The values of ΦBo and n changed from 0.173 eV to 0.837 eV and 6.60 to 2.85 with increasing temperature from 60 K to 340 K. This positive temperature-coefficient (α) of ΦBo is inagreement with the bandgap of semiconductor or barrier height (BH) for the ideal diode. The calculated higher value of n at low temperatures was attributed to the inhomogeneities of BH rather than the interlayer, surface-states (Nss), and image-force lowering. With lowing temperatures, CCMs may be governed by tunneling over the lower barriers, via Nss, and generation recombination (GR), as well as TE and hence a complete description of CCM and understanding of the formation BH, remain a compelling problem. Nss-(Ec-Ess) profile was also obtained from IF-VF data for each temperature.

Schottky Barrier Height and Image Force Lowering in Monolayer MoS2 Field Effect Transistors

Understanding the nature of the barrier height in a two-dimensional semiconductor/metal interface is an important step for embedding layered materials in future electronic devices. We present direct measurement of the Schottky barrier height and its lowering in the transition metal dichalcogenide (TMD)/metal interface of a field effect transistor. It is found that the barrier height at the gold/ single-layer molybdenum disulfide (MoS2) interfaces decreases with increasing drain voltage, and this lowering reaches 0.5–1 V We also show that increase of the gate voltage induces additional barrier lowering.