A multiscale generative model to understand disorder in domain boundaries

A continuing challenge in atomic resolution microscopy is to identify significant structural motifs and their assembly rules in synthesized materials with limited observations. Here we propose and validate a simple and effective hybrid generative model capable of predicting unseen domain boundaries in a potassium sodium niobate thin film from only a small number of observations, without expensive first-principles calculation. Our results demonstrate that complicated domain boundary structures can arise from simple interpretable local rules, played out probabilistically. We also found new significant tileable boundary motifs and evidence that our system creates domain boundaries with the highest entropy. More broadly, our work shows that simple yet interpretable machine learning models can help us describe and understand the nature and origin of disorder in complex materials

Strain‐Driven Bidirectional Spin Orientation Control in Epitaxial High Entropy Oxide Films

High entropy oxides (HEOs), based on the incorporation of multiple-principal cations into the crystal lattice, offer the possibility to explore previously inaccessible oxide compositions and unconventional properties. Here it is demonstrated that despite the chemical complexity of HEOs external stimuli, such as epitaxial strain, can selectively stabilize certain magneto-electronic states. Epitaxial (Co$_{0.2}$Cr$_{0.2}$Fe$_{0.2}$Mn$_{0.2}$Ni$_{0.2}$)$_{3}$O$_{4}$-HEO thin films are grown in three different strain states: tensile, compressive, and relaxed. A unique coexistence of rocksalt and spinel-HEO phases, which are fully coherent with no detectable chemical segregation, is revealed by transmission electron microscopy. This dual-phase coexistence appears as a universal phenomenon in (Co$_{0.2}$Cr$_{0.2}$Fe$_{0.2}$Mn$_{0.2}$Ni$_{0.2}$)$_{3}$O$_{4}$ epitaxial films. Prominent changes in the magnetic anisotropy and domain structure highlight the strain-induced bidirectional control of magnetic properties in HEOs. When the films are relaxed, their magnetization behavior is isotropic, similar to that of bulk materials. However, under tensile strain, the hardness of the out-of-plane (OOP) axis increases significantly. On the other hand, compressive straining results in an easy OOP magnetization and a maze-like magnetic domain structure, indicating the perpendicular magnetic anisotropy. Generally, this study emphasizes the adaptability of the high entropy design strategy, which, when combined with coherent strain engineering, opens additional prospects for fine-tuning properties in oxides

ATOMIC SCALE STRUCTURE AND PROPERTIES OF FAULTED ALKALI NIOBATE THIN FILMS

Ph.DDOCTOR OF PHILOSOPHY (NUSGS

3D finite element analysis of tine cultivator and soil deformation

For effective tillage, design and selection of tillage tool according to soil type and condition is very important. The present study is carried out for in-depth investigation of different types of shovels of tine cultivator and behavior of soil in response to loads subjected during tillage using finite element analysis. Different types of shovels like reversible, duck foot, seed drill and cultivator shovel are simulated with different types of soil like sand, clay and loam. The origination, level and distribution of stresses and deformations in shovels experienced in different types of soils are probed. Furthermore, high stressed and crack sensitive regions are identified. The stresses of 18, 53, 64 MPa are generated in reversible shovel of tine cultivator during ploughing in sandy, clay and loamy soil respectively. In addition, results of different shovels are compared, and it is found that the duck foot type shovel experiences highest stress and deformation. The duck foot shovel experiences about 20 and 71% higher stresses in loam compared to that in clay and sand respectively. Moreover, the study of soil mechanical behavior shows that the soil block (clay soil) experiences maximum stress of 34 MPa while tilling with reversible shovel. The statistical analysis is also conducted that shows high significance of simulation results

Wafer-scale solution-processed 2D material analog resistive memory array for memory-based computing

10.1038/s41467-022-30519-wNATURE COMMUNICATIONS13

Quasi-Paired Pt Atomic Sites on Mo2C Promoting Selective Four-Electron Oxygen Reduction

10.1002/advs.202101344Advanced Science818210134

Alkali-deficiency driven charged out-of-phase boundaries for giant electromechanical response

10.1038/s41467-021-23107-xNature Communications121284

Strain‐Driven Bidirectional Spin Orientation Control in Epitaxial High Entropy Oxide Films

High entropy oxides (HEOs), based on the incorporation of multiple-principal cations into the crystal lattice, offer the possibility to explore previously inaccessible oxide compositions and unconventional properties. Here it is demonstrated that despite the chemical complexity of HEOs external stimuli, such as epitaxial strain, can selectively stabilize certain magneto-electronic states. Epitaxial (Co0.2 Cr0.2 Fe0.2 Mn0.2 Ni0.2 )3 O4 -HEO thin films are grown in three different strain states: tensile, compressive, and relaxed. A unique coexistence of rocksalt and spinel-HEO phases, which are fully coherent with no detectable chemical segregation, is revealed by transmission electron microscopy. This dual-phase coexistence appears as a universal phenomenon in (Co0.2 Cr0.2 Fe0.2 Mn0.2 Ni0.2 )3 O4 epitaxial films. Prominent changes in the magnetic anisotropy and domain structure highlight the strain-induced bidirectional control of magnetic properties in HEOs. When the films are relaxed, their magnetization behavior is isotropic, similar to that of bulk materials. However, under tensile strain, the hardness of the out-of-plane (OOP) axis increases significantly. On the other hand, compressive straining results in an easy OOP magnetization and a maze-like magnetic domain structure, indicating the perpendicular magnetic anisotropy. Generally, this study emphasizes the adaptability of the high entropy design strategy, which, when combined with coherent strain engineering, opens additional prospects for fine-tuning properties in oxides

Strain‐Driven Bidirectional Spin Orientation Control in Epitaxial High Entropy Oxide Films

High entropy oxides (HEOs), based on the incorporation of multiple‐principal cations into the crystal lattice, offer the possibility to explore previously inaccessible oxide compositions and unconventional properties. Here it is demonstrated that despite the chemical complexity of HEOs external stimuli, such as epitaxial strain, can selectively stabilize certain magneto‐electronic states. Epitaxial (Co₀.₂Cr₀.₂Fe₀.₂Mn₀.₂Ni₀.₂)₃O₄‐HEO thin films are grown in three different strain states: tensile, compressive, and relaxed. A unique coexistence of rocksalt and spinel‐HEO phases, which are fully coherent with no detectable chemical segregation, is revealed by transmission electron microscopy. This dual‐phase coexistence appears as a universal phenomenon in (Co₀.₂Cr₀.₂Fe₀.₂Mn₀.₂Ni₀.₂)₃O₄ epitaxial films. Prominent changes in the magnetic anisotropy and domain structure highlight the strain‐induced bidirectional control of magnetic properties in HEOs. When the films are relaxed, their magnetization behavior is isotropic, similar to that of bulk materials. However, under tensile strain, the hardness of the out‐of‐plane (OOP) axis increases significantly. On the other hand, compressive straining results in an easy OOP magnetization and a maze‐like magnetic domain structure, indicating the perpendicular magnetic anisotropy. Generally, this study emphasizes the adaptability of the high entropy design strategy, which, when combined with coherent strain engineering, opens additional prospects for fine‐tuning properties in oxides

Strain‐Driven Bidirectional Spin Orientation Control in Epitaxial High Entropy Oxide Films

Abstract High entropy oxides (HEOs), based on the incorporation of multiple‐principal cations into the crystal lattice, offer the possibility to explore previously inaccessible oxide compositions and unconventional properties. Here it is demonstrated that despite the chemical complexity of HEOs external stimuli, such as epitaxial strain, can selectively stabilize certain magneto‐electronic states. Epitaxial (Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)3O4‐HEO thin films are grown in three different strain states: tensile, compressive, and relaxed. A unique coexistence of rocksalt and spinel‐HEO phases, which are fully coherent with no detectable chemical segregation, is revealed by transmission electron microscopy. This dual‐phase coexistence appears as a universal phenomenon in (Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)3O4 epitaxial films. Prominent changes in the magnetic anisotropy and domain structure highlight the strain‐induced bidirectional control of magnetic properties in HEOs. When the films are relaxed, their magnetization behavior is isotropic, similar to that of bulk materials. However, under tensile strain, the hardness of the out‐of‐plane (OOP) axis increases significantly. On the other hand, compressive straining results in an easy OOP magnetization and a maze‐like magnetic domain structure, indicating the perpendicular magnetic anisotropy. Generally, this study emphasizes the adaptability of the high entropy design strategy, which, when combined with coherent strain engineering, opens additional prospects for fine‐tuning properties in oxides