Article
Physics, Applied
M. J. Zou, Y. L. Tang, Y. P. Feng, W. R. Geng, X. L. Ma, Y. L. Zhu
Summary: This research investigates the impact of flexoelectricity on nanoscale ferroelectric thin films, revealing that the domain switching in strain-gradient PbTiO3 films is influenced by an additional flexoelectric field. The study proposes an effective method to stabilize the ferroelectric polarization in nanoscale ferroelectric films.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Alexandre Silva, Ignasi Fina, Florencio Sanchez, Jose P. B. Silva, Luis Marques, Veniero Lenzi
Summary: We investigated the influence of La content on the structural and ferroelectric properties of epitaxial HfO2 films. It was found that 2-5 at. % La-doped HfO2 films exhibit optimum remanent polarization and reduced coercive field. Density functional theory calculations supported the experimental results and revealed that the polarization switching in epitaxial La:HfO2 films can be understood based on the synergetic contribution of a non-ferroelectric monoclinic phase and La doping itself.
MATERIALS TODAY PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Ekaterina Kondratyuk, Anastasia Chouprik
Summary: Ferroelectric polycrystalline HfO2 thin films are a promising material for novel non-volatile ferroelectric memories. This study proposes a new model of switching kinetics that successfully explains the observed retardation behavior in Hf0.5Zr0.5O2 (HZO)-based capacitors.
Article
Physics, Applied
Lin Liu, Lin Lei, Xiaomei Lu, Fang Mei, Min Zhou, Xueli Hu, Shuo Yan, Fengzhen Huang, Jinsong Zhu
Summary: In this study, Bi0.8La0.2FeO3 (BLFO) films were directly deposited on low-resistance Si substrates using the pulsed laser deposition method. The hysteresis loops of BLFO/Si samples exhibit unique characteristics, potentially due to the formation of a p-n junction between the BLFO film and Si substrate, with oxygen vacancies accumulating near the interface.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Wanlin Zhu, John Hayden, Fan He, Jung-In Yang, Pannawit Tipsawat, Mohammad D. Hossain, Jon-Paul Maria, Susan Trolier-McKinstry
Summary: This study reveals the temperature dependence of ferroelectric switching in Al0.84Sc0.16N, Al0.93B0.07N, and AlN thin films, showing strong temperature dependence on polarization reversal and coercive field, while minimal temperature dependence on remanent polarization values. The relative permittivity increased within a certain temperature range, and polarization reversal was confirmed through piezoelectric coefficient analysis and chemical etching. Models based on thermal activation suggest a distribution of pinning sites or nucleation barriers regulates the switching behavior with an average activation energy near 28 meV.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Zhi Yun Yue, Zhi Dong Zhang, Zhan Jie Wang
Summary: This study achieved high resistive switching effect in ferroelectric memristors by embedding appropriate concentrations of Au nanoparticles in Pb(Zr0.40Ti0.60)O3 films. The addition of Au nanoparticles improved leakage current and maintained ferroelectric polarization. The resistive switching on/off ratio reached 10^6 with 3 mol% Au nanoparticles, improving the resistance-variable switching ratio by two orders of magnitude compared to pure PCZT films. Multi-level data storage was also achieved under different bias voltages.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Multidisciplinary Sciences
Blai Casals, Guillaume F. Nataf, Ekhard K. H. Salje
Summary: Field induced domain wall displacements define ferroelectric/ferroelastic hysteresis loops, and the analysis shows that the avalanche characteristics in different ferroelectric materials are similar, with energy, area, and perimeter of the switched regions following power law distributions.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Martin F. Sarott, Marta D. Rossell, Manfred Fiebig, Morgan Trassin
Summary: This study demonstrates the ability to continuously modulate the remanent polarization at the nanoscale in PbZr0.52Ti0.48O3 films by driving the system towards the instability at the morphotropic phase boundary, achieving multilevel switching.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Shoji Ishibashi, Reiji Kumai, Sachio Horiuchi
Summary: Some organic ferroelectrics, such as DHBA and Hdabco-ReO4, have two possible switching modes: molecular reorientation and proton transfer. This study demonstrates a straightforward method to identify the ferroelectric switching mechanism by illustrating the relationship between polarization vectors and using the theoretical background for the sign of the piezoelectric coefficient. The comparison between theoretically calculated piezoelectric coefficients and experimental results confirms the switching mode of each compound.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Wei-Qiang Liao, Bin-Bin Deng, Zhong-Xia Wang, Ting-Ting Cheng, Yan-Ting Hu, Shu-Ping Cheng, Ren-Gen Xiong
Summary: SA-PFA is an organic molecular ferroelectric material with light-triggered reversible structural changes, showing clear ferroelectricity and optically induced ferroelectric polarization switching behavior. The reversible photoisomerization effect of SA-PFA enables potential application in light-controlled ferroelectric devices.
Article
Chemistry, Multidisciplinary
Puqi Hao, Shuaizhi Zheng, Binjian Zeng, Tao Yu, Zhibin Yang, Luocheng Liao, Qiangxiang Peng, Qijun Yang, Yichun Zhou, Min Liao
Summary: This study demonstrates that the composition-graded Hf1-xZrxO2 ferroelectric thin film has more than two times faster polarization switching speed and excellent ferroelectricity and improved endurance characteristics compared to the conventional composition-uniform HfO2 thin film. It is discovered that the built-in gradient composition leads to a shift from nucleation-limited-switching mechanism to domain-wall growth mechanism, resulting in the faster speed and better endurance of the composition-graded HZO thin film. These findings not only reveal the physical mechanisms but also provide a new strategy for memory devices with faster speed and higher endurance.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Taekyong Kim, Jesus A. del Alamo, Dimitri A. Antoniadis
Summary: The existence of negative capacitance (NC) and the switching dynamics of ferroelectric HfZrO2 (FE-HZO) metal-ferroelectric-Metal (MFM) structures are still contentious and unclear. This work provides a detailed study of the switching characteristics of HZO MFM structures and demonstrates that there is no evidence of NC effect. The study emphasizes the crucial role of parasitics in the dynamic characterization of R-MFM circuits.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Physical
Yuzhong Hu, Lu You, Bin Xu, Tao Li, Samuel Alexander Morris, Yongxin Li, Yehui Zhang, Xin Wang, Pooi See Lee, Hong Jin Fan, Junling Wang
Summary: The study demonstrates a large shear strain in the hybrid ferroelectric C6H5N(CH3)(3)CdCl3, achieving up to 21.5% strain, two orders of magnitude greater than traditional piezoelectrics. This is attributed to organic molecules preventing 180 degrees polarization switching, showing potential for lightweight and high-energy-density devices.
Article
Chemistry, Multidisciplinary
Inho Song, Liyan You, Ke Chen, Won-June Lee, Jianguo Mei
Summary: Homogeneous chiral electrochromics using chiral assembly of conjugated polymers have been developed through a transient solidification process with molecular chiral templates. The circular dichroism can be tuned by adjusting the doping level of the electrochemically active polymer films. The differential circularly polarized transmission in the chiral see-through display can make a well-resolved color change, demonstrating proof-of-concept devices for information encryption.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Hao Pan, Zishen Tian, Megha Acharya, Xiaoxi Huang, Pravin Kavle, Hongrui Zhang, Liyan Wu, Dongfang Chen, John Carroll, Robert Scales, Cedric J. G. Meyers, Kathleen Coleman, Brendan Hanrahan, Jonathan E. E. Spanier, Lane W. W. Martin
Summary: It is demonstrated that the polarization switching behavior of antiferroelectrics can be strongly influenced and effectively regulated by point defects. In the case of PbZrO3 films, the decrease in oxygen pressure during deposition leads to unexpected ferroelectric-like polarization switching, attributed to the creation of bombardment-induced point-defect complexes. These complexes pin the antiferroelectric-ferroelectric phase boundaries and delay the phase transition under changing field. By controlling the concentration of defect complexes, the dielectric tunability of PbZrO3 can be adjusted, including the conversion of positive and negative tunability near zero field.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Koppole Kamakshi, J. P. B. Silva, N. S. Kiran Kumar, K. C. Sekhar, M. Pereira
MRS COMMUNICATIONS
(2020)
Article
Chemistry, Multidisciplinary
Kevin Varghese Alex, Parthiban Tamil Pavai, Radhasaran Rugmini, Madavi Shiva Prasad, Koppole Kamakshi, Koppole Chandra Sekhar
Article
Materials Science, Composites
Tarun Garg, Venkateswarlu Annapureddy, K. C. Sekhar, Dae-Yong Jeong, Navneet Dabra, Jasbir S. Hundal
POLYMER COMPOSITES
(2020)
Review
Chemistry, Physical
Jose P. B. Silva, Koppole C. Sekhar, Hao Pan, Judith L. MacManus-Driscoll, Mario Pereira
Summary: Dielectric capacitors are optimal energy storage systems with high power density and long lifetime. HfO2 and ZrO2-based thin films show strong potential, particularly in their ferroelectric properties that play a significant role in various modern technologies.
ACS ENERGY LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Tarun Garg, Venkateswarlu Annapureddy, K. C. Sekhar, Dae-Yong Jeong, Navneet Dabra, Jasbir S. Hundal
Summary: PVDF is a semi-crystalline ferroelectric polymer that can be stabilized in its distinct electroactive polymorphs through selective processing techniques. The introduction of BCZT ceramic particles in PVDF matrix enhances the overall crystallinity of the polymer but has no significant effect on PVDF phase stabilization. The dielectric studies show that the composite films with BCZT content have higher relative permittivity and lower loss tangent values, improving the overall electrical properties of ceramic/polymer composites.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Jose P. B. Silva, Raluca F. Negrea, Marian C. Istrate, Sangita Dutta, Hugo Aramberri, Jorge Iniguez, Fabio G. Figueiras, Corneliu Ghica, Koppole C. Sekhar, Andrei L. Kholkin
Summary: Zirconia- and hafnia-based thin films have attracted significant attention due to their ferroelectric behavior at the nanoscale. This study reveals a new ferroelectric rhombohedral phase of ZrO2 in thin films grown on (111)-Nb:SrTiO3 substrates, exhibiting high ferroelectric polarization and low coercive field with characteristics in agreement with the nucleation limited switching (NLS) model for ferroelectric domain reversal.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Review
Materials Science, Multidisciplinary
Ampattu R. Jayakrishnan, Anuj Kumar, Sahana Druvakumar, Rosmin John, Meera Sudeesh, Venkata Sreenivas Puli, Jose P. B. Silva, Maria J. M. Gomes, Koppole C. Sekhar
Summary: Scientific research has shown that ferroelectric materials, particularly inorganic ferroelectric materials, play a crucial role in flexible energy devices. These devices, including energy harvesters, infrared sensors, and energy storage capacitors, focus on self-powered flexible sensors and energy harvesters to promote sustainability. By combining inorganic ferroelectric materials with organic/inorganic polymers, flexible devices can meet the requirements of high mechanical strength, piezoelectric and pyroelectric coefficients, and energy storage properties essential for harvesting, sensing, and storage applications. This review article provides a systematic analysis of flexible inorganic ferroelectric-based energy materials, discussing the importance of inorganic ferroelectrics and their current state-of-the-art in energy harvesting, IR sensing, and energy storage. It also explores the challenges and future prospects of developing high-quality flexible inorganic ferroelectric devices for real-world applications.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Materials Science, Ceramics
Muhassinah Tasneem, Carlos R. P. Monteiro, N. S. Kiran Kumar, J. P. B. Silva, K. C. Sekhar, K. Kamakshi, M. Pereira
Summary: In this work, the effects of thickness on the properties of BZCT-STO thin films were studied. XRD analysis showed a polycrystalline tetragonal structure with strain relaxation in thicker films. SEM analysis revealed a dense columnar structure with varying grain size. The P-E loops indicated enhanced relaxor behavior and the RS effect was significant at low thickness. The energy storage properties were investigated, showing robust performance in a wide frequency range and over a large number of cycles.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Kevin V. Alex, Jose P. B. Silva, Koppole Kamakshi, Koppole C. Sekhar
Summary: This study demonstrates the fabrication of a highly efficient ternary heterostructure photocatalyst composed of ferroelectric BaTiO3 (BTO), semiconductor MoO3, and plasmonic silver nanoparticles (Ag NPs). The BaTiO3/MoO3/Ag (BMA) heterostructure exhibits superior photodegradation and photocatalytic efficiency compared to its binary counterparts. The enhanced photocatalytic activity in the BMA heterostructure is attributed to the enhanced interfacial electric field and electron transfer towards the top Ag NPs layer. The improved charge carrier generation and separation in the BMA heterostructure are evident from the higher resistive switching ratio, increased difference in voltage minima, and enhanced photocurrent generation observed in the I-V characteristics.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
A. R. Jayakrishnan, J. P. B. Silva, K. Kamakshi, V Annapureddy, I. F. Mercioniu, K. C. Sekhar
Summary: The study presents a novel strategy to enhance the dielectric breakdown strength and energy storage performance of lead-free relaxor ferroelectric ceramics by fabricating semiconductor/relaxor 0-3 type composites. The energy storage properties were found to be optimal at 1 wt. % ZnO, with a recoverable energy density of 2.61 J/cm(3) and an efficiency of 74.2%.
JOURNAL OF SCIENCE-ADVANCED MATERIALS AND DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Jose P. B. Silva, Koppole C. Sekhar, Katerina Veltruska, Vladimir Matolin, Raluca F. Negrea, Corneliu Ghica, Marcelo J. S. Oliveira, Joaquim Agostinho Moreira, Mario Pereira, Maria J. M. Gomes
ACS APPLIED ELECTRONIC MATERIALS
(2020)
Article
Chemistry, Physical
J. P. B. Silva, J. M. B. Silva, K. C. Sekhar, H. Palneedi, M. C. Istrate, R. F. Negrea, C. Ghica, A. Chahboun, M. Pereira, M. J. M. Gomes
JOURNAL OF MATERIALS CHEMISTRY A
(2020)
Article
Chemistry, Physical
J. P. B. Silva, E. M. F. Vieira, J. M. B. Silva, K. Gwozdz, F. G. Figueiras, K. Veltruska, V. Matolin, M. C. Istrate, C. Ghica, K. C. Sekhar, A. L. Kholkin, L. M. Goncalves, A. Chahboun, M. Pereira
JOURNAL OF MATERIALS CHEMISTRY A
(2020)
Article
Nanoscience & Nanotechnology
A. R. Jayakrishnan, Penna Venkata Karthik Yadav, J. P. B. Silva, K. C. Sekhar
JOURNAL OF SCIENCE-ADVANCED MATERIALS AND DEVICES
(2020)
