232 citations · 637 across the 18 of their papers we have counts for
18 papers
Atomic-scale theory of robust out-of-plane ferroelectricity in ultrathin films
Fengbo Yuan, Yujia Teng, Karin M. Rabe +1
Ferroelectricity in ultrathin films, characterized by robust switchable out-of-plane polarization, is key to next-generation nanoelectronics. Although the macroscopic theory of fer…
Bridging experiment and theory of relaxor ferroelectrics at the atomic scale with multislice electron ptychography
Menglin Zhu, Michael Xu, Yubo Qi +7
Introducing structural and/or chemical heterogeneity into otherwise ordered crystals can dramatically alter material properties. Lead-based relaxor ferroelectrics are a prototypica…
"Double-path" ferroelectrics and the sign of the piezoelectric response
Yubo Qi, Sebastian E. Reyes-Lillo, Karin M. Rabe
In this work, we propose a class of ferroelectrics (which we denote "double-path" ferroelectrics), characterized by two competing polarization switching paths for which the change…
Vibrational fingerprints of ferroelectric hafnia
Shiyu Fan, Sobhit Singh, Xianghan Xu +6
Hafnia (HfO2) is a promising material for emerging chip applications due to its high-k dielectric behaviour, suitability for negative capacitance heterostructures, scalable ferroel…
Polarization switching mechanism in HfO from first-principles lattice mode analysis
Yubo Qi, Sobhit Singh, Karin M. Rabe
In this work, we carry out first-principles calculations and lattice mode analysis to investigate the polarization switching mechanism in HfO. Because the stability of the pola…
Electron-lattice coupling contributions to polarization switching in charge-order-induced ferroelectrics
Yubo Qi, Karin M. Rabe
We carry out first-principles density-functional-theory calculations to elucidate the polarization switching mechanism in charge-ordering-induced ferroelectrics based on the protot…
Kinetically-stabilized Ferroelectricity in Bulk Singlecrystalline HfO2:Y without Wake-up Effects
Xianghan Xu, Fei-Ting Huang, Yubo Qi +6
HfO2, a simple binary oxide, holds ultra-scalable ferroelectricity integrable into silicon technology. Polar orthorhombic (Pbc21) form in ultra-thin-films ascribes as the plausible…
Phase Competition in HfO with Applied Electric Field from First Principles
Yubo Qi, Karin M. Rabe
In this work, the results of first-principles density-functional-theory calculations are used to construct the energy landscapes of HfO and its Y and Zr substituted derivatives…
Negative piezoelectricity in low--dimensional materials
Yubo Qi, Andrew M. Rappe
In this study, we investigate the underlying mechanisms of the negative piezoelectricity in low--dimensional materials by carrying out first--principles calculations. Two--dimensio…
Stabilization of competing ferroelectric phases of HfO under epitaxial strain
Yubo Qi, Sobhit Singh, Claudia Lau +6
Hafnia (HfO)-based thin films have promising applications in nanoscale electronic devices due to their robust ferroelectricity and integration with silicon. However, HfO ha…
Domain Wall Enabled Steep Slope Switching in MoS Transistors Towards Hysteresis-Free Operation
Jingfeng Song, Yubo Qi, Zhiyong Xiao +6
The device concept of ferroelectric-based negative capacitance (NC) transistors offers a promising route for achieving energy-efficient logic applications that can outperform the c…
Sr-induced dipole scatter in BST: Insights from MD simulations using a transferable bond valence-based interatomic potential
Robert B. Wexler, Yubo Qi, Andrew M. Rappe
In order to design next-generation ferroelectrics, a microscopic understanding of their macroscopic properties is critical. One means to achieving an atomistic description of ferro…
Tribopolymer Formation Mechanism on the RuO(110) Surface
Jing Yang, Yubo Qi, Hyeong-Seok D. Kim +1
Tribopolymer formed on the contacts of microelectromechanical and nanoelectromechanical system (MEMS/NEMS) devices is a major concern hampering their practical use in information t…
Ultra-fast electric field control of giant electrocaloric effect in ferroelectrics
Yubo Qi, Shi Liu, Aaron M. Lindenberg +1
There is a surge of interest in developing environmentally friendly cooling technology based on the solid--state electrocaloric effect (ECE). Here, we point out that negative ECE w…
Adsorption of Benzene on the RuO2(110) Surface
Hyeong-Seok D. Kim, Jing Yang, Yubo Qi +1
Hydrocarbon tribopolymer, a type of polymer formed due to friction between surfaces, is a major impediment to the development of micro- and nanoelectromechanical systems (MEMS/NEMS…
Atomistic Description for Temperature-Driven Phase Transitions in BaTiO
Yubo Qi, Shi Liu, Ilya Grinberg +1
Barium titanate (BaTiO) is a prototypical ferroelectric perovskite that undergoes the rhombohedral-orthorhombic-tetragonal-cubic phase transitions as the temperature increases.…
Theoretical Modeling of Tribochemical Reaction on Pt and Au Contacts: Mechanical Load and Catalysis
Yubo Qi, Jing Yang, Andrew M. Rappe
Micro-electro-mechanical system and nano-electro-mechanical system (MEMS and NEMS) transistors are considered promising for size-reducing and power-maximizing electronic devices. H…
Low Operation Voltage Ferroelectric Field-Effect Transistor Based on Polarization Rotation Effect
Yubo Qi, Andrew M. Rappe
The effect of polarization rotation on the performance of metal oxide semiconductor field-effect transistors was investigated with a Landau-Ginzburg-Devonshire theory based model.…