Article
Engineering, Electrical & Electronic
Taehwan Jung, Jaemin Shin, Changhwan Shin
Summary: The study found that the increased remanent polarization and charge trapping are the main reasons for the shift of coercive voltage in silicon-doped hafnium oxide thin films. Different factors, such as Si concentration, thickness of the ferroelectric layer, and thickness of the interface layer, affect the magnitude of coercive voltage shift and depolarization field differently. The results suggest that the discussed strategy is a promising approach for designing FE-HfO2 devices.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Rabia Tahir, Sabeen Fatima, Syedah Afsheen Zahra, Deji Akinwande, Hu Li, Syed Hassan Mujtaba Jafri, Syed Rizwan
Summary: In this study, a simple approach to observe frequency-dependent ferroelectricity and multiferroicity in 2D Ti3C2Tx MXene film at room-temperature was reported. The results confirmed the presence of strong magneto-electric coupling and showed the control of electric polarization by magnetic fields. The ferroelectric Ti3C2Tx MXene film was also employed as an active layer in resistive data storage devices, resulting in stable switching behavior and improved on/off ratio.
NPJ 2D MATERIALS AND APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Chhatra R. Joshi, Mahendra Acharya, Gary J. Mankey, Arunava Gupta
Summary: This study investigates the effects of thickness on the room-temperature polarization-voltage (P-V) hysteresis loop, leakage current, and average domain size of multiferroic BiFeO3 (BFO) films. The results demonstrate that BFO films indeed follow the Ishibashi-Orihara (I-O) model and the Kay-Dunn scaling law at room temperature. The dimensionality of the observed domains using piezoresponse force microscopy imaging is consistent with the results from the I-O model and Kittel's law. These findings provide valuable insights into the fundamental properties that govern the switching kinetics of BFO and their relevance for next-generation logic and memory devices operating at a wide range of frequencies.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Multidisciplinary Sciences
Weng Fu Io, Sin -Yi Pang, Lok Wing Wong, Yuqian Zhao, Ran Ding, Jianfeng Mao, Yifei Zhao, Feng Guo, Shuoguo Yuan, Jiong Zhao, Jiabao Yi, Jianhua Hao
Summary: Robust out-of-plane ferroelectricity is observed in 2D vdW CuCrP2S6, providing important insights into its nature and potential for advanced device applications.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Ceramics
Qiyuan Zhou, Zhanhui Peng, Fudong Zhang, Qizhen Chai, Di Wu, Pengfei Liang, Lingling Wei, Xiaolian Chao, Zupei Yang
Summary: BNT-CS-xST ceramics with controlled microstructure and electrical properties have been successfully prepared, achieving high polarization strength and high breakdown strength simultaneously, as well as high energy storage density, showing great potential for commercial applications in energy storage materials.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Yang Zhang, Hui Wang, Koki Tachiyama, Tsukasa Katayama, Yinghao Zhu, Si Wu, Hai-Feng Li, Jinghong Fang, Qin Li, Yun Shi, Ling Wang, Zhengqian Fu, Fangfang Xu, Jianding Yu, Shintaro Yasui, Mitsuru Itoh
Summary: In this study, epsilon-Fe2O3 single crystals were successfully synthesized by codoping with Ga3+ and Sc3+, demonstrating both room-temperature ferrimagnetism and spontaneous ferroelectric polarization. The single crystals displayed strong magnetic anisotropy along the a-axis at 300 K, with magnetic transition temperature and coercive field decreasing with increasing x. Furthermore, a magnetic-field-induced modulation of polarization was observed at a relatively high temperature of 150 K with a magnetoelectric coefficient of (2-5) x 10(-11) S/m.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Maximilian Merkel, Rico Huhnstock, Meike Reginka, Michael Vogel, Arno Ehresmann, Hubert Glowinski, Piotr Kuswik
Summary: The study revealed a viscous decrease of magnetization in a prototypical polycrystalline in-plane exchange bias system, attributed to a rotatable magnetic anisotropy resulting from thermally unstable antiferromagnetic grains coupled to the probed ferromagnet. This highlights the importance of understanding minor loop behavior, especially for systems susceptible to dynamic changes on the hysteresis loop timescale.
Article
Nanoscience & Nanotechnology
D. -G. Jin, S. -G. Kim, H. Jeon, E. -J. Park, S. -H. Kim, Y-Y. Kim, H. -Y. Yu
Summary: A ferroelectric field-effect transistor based on Hf0.5Zr0.5O2 was proposed for a high-performance artificial synaptic device by reducing interface trap density. With polarization in the Hf0.5Zr0.5O2 ferroelectric layer, the threshold voltage was precisely controlled to achieve synaptic characteristics. However, interface traps caused degradation of synaptic characteristics. Oxygen plasma treatment was performed to minimize this degradation. Our study demonstrated a promising method for implementing a high-accuracy, low-power neuromorphic system with progressed artificial synaptic devices.
MATERIALS TODAY NANO
(2023)
Article
Multidisciplinary Sciences
Qianqian Yang, Jingcong Hu, Yue-Wen Fang, Yueyang Jia, Rui Yang, Shiqing Deng, Yue Lu, Oswaldo Dieguez, Longlong Fan, Dongxing Zheng, Xixiang Zhang, Yongqi Dong, Zhenlin Luo, Zhen Wang, Huanhua Wang, Manling Sui, Xianran Xing, Jun Chen, Jianjun Tian, Linxing Zhang
Summary: We developed a bismuth oxide film with a layered structure that can stabilize the ferroelectric state at a thickness of 1 nanometer. The film can be grown on different substrates using a cost-effective chemical solution deposition technique. The thin films, ranging from 1 to 4.56 nanometers, exhibited a standard ferroelectric hysteresis loop and relatively large remanent polarization. First-principles calculations confirmed the film's structure and suggested it to be a lone pair-driven ferroelectric material. The design of ultrathin ferroelectric films holds great potential for atomic-scale electronic device manufacturing.
Article
Physics, Applied
Keisuke Yazawa, Andriy Zakutayev, Geoff L. Brennecka
Summary: This study presents a thermodynamic analysis of nitride ferroelectric materials using the classic Landau-Devonshire approach. The results show that the energy barrier's strain sensitivity in wurtzite ferroelectrics is higher compared to classic perovskite ferroelectrics.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Stephan Lange, Andreas Ricoeur
Summary: Macroscopic properties of ferroelectrics are influenced by processes on micro and meso scales. Multiscale modeling is necessary to consider three interacting scales, with the condensed method being an efficient tool. Parameters of the constitutive approach are adjusted based on experimental values to simulate grain sizes and domain evolution.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Ehsan Faridi, Se Kwon Kim, Giovanni Vignale
Summary: The study reveals that spin waves are reflected by a sharp domain wall in an antiferromagnetic spin chain, with the reflection coefficient increasing as the domain wall width decreases. In the case of an atomically sharp domain wall, the reflection of spin waves depends on the circular polarization, allowing for mainly reflection for one polarization and partial transmission for the other, leading to the realization of an atomic-scale spin-wave polarizer.
Article
Physics, Multidisciplinary
Leonid Afremov, Ilia Iliushin, Maria Shmykova
Summary: In this work, a theoretical study was conducted on the hysteresis characteristics of core/shell nanoparticles, focusing on their size, interphase exchange, and interparticle magnetic interactions. The results showed that increasing the size of nanoparticles leads to an increase in their saturation magnetization and remanent magnetization, as well as non-monotonic or monotonic changes in the coercive field. Furthermore, the study revealed that interphase exchange interaction has a significant effect on the coercive force and remanent saturation magnetization of Fe/Fe3O4 nanoparticles, while its effect on Co/Au nanoparticles is weak. Additionally, the interparticle magnetic interactions decrease the coercive force and remanent saturation magnetization of core/shell nanoparticles, and the rate of decrease in hysteresis characteristics is higher for larger nanoparticles.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Evgeny A. A. Gorbachev, Liudmila N. N. Alyabyeva, Miroslav V. V. Soshnikov, Vasily A. A. Lebedev, Anatolii V. V. Morozov, Ekaterina S. S. Kozlyakova, Asmaa Ahmed, Artem A. A. Eliseev, Lev A. A. Trusov
Summary: In this study, we sintered metastable epsilon-Fe2O3 nanoparticles into nanoceramics with a high density and demonstrated their unique magnetic properties. The sintered ceramics retained the initial nanoparticles' giant coercivity and sub-terahertz absorption. We proposed a simple explanation for the low-temperature dynamics of the magnetic parameters and discussed the potential application of nanoceramics in sub-terahertz spin-pumping.
MATERIALS HORIZONS
(2023)
Article
Engineering, Electrical & Electronic
Hannes Dahlberg, Anton E. O. Persson, Robin Athle, Lars-Erik Wernersson
Summary: The ferroelectric-antiferroelectric transition in Hf1-xZrxO2 (HZO) is demonstrated in a metal-ferroelectric-semiconductor stack based on InAs for the first time. The integration of ferroelectric thin films in nonvolatile operations is highly relevant for future electronic devices. The increase in Zr fraction leads to enhanced nonvolatility and a transition from ferroelectric to antiferroelectric behavior.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Physics, Applied
Akinori Tateyama, Yoshiharu Ito, Takahisa Shiraishi, Minoru Kurosawa, Hiroshi Funakubo
Summary: The dependence of output power of piezoelectric vibration energy harvesters on film thickness was investigated using (K,Na)NbO3 films on SrTiO3 substrates. Increasing film thickness led to a decrease in Q(m) and output power under the same input acceleration condition. However, when attached to a larger volume Al plate, the output power increased significantly due to almost constant Q(m) value despite the increase in film thickness.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
K. Hatashita, T. Tsuchiya, M. Okazaki, M. Nakano, S. A. Anggraini, K. Hirata, S. Ohmagari, M. Uehara, H. Yamada, M. Akiyama, S. Shikata
Summary: In this study, the Sc concentration dependency of Sc (x) Al1-x N/AlN/poly-crystalline diamond/Si surface acoustic wave (SAW) characteristics at high Sc was investigated. The 3.8 GHz one-port resonator fabricated on Sc0.43Al0.57N showed excellent electro-mechanical coupling coefficient (K (2)) of 6.34% for 2nd mode Sezawa wave, enabling wide bandwidth in high frequency applications. The temperature coefficient of frequency for the device fabricated with Sc concentration of 42.9% was -40 to -50 ppm deg(-1), smaller than conventional high K-2 bulk materials such as LiNbO3. This study reveals the possibility of a high K-2 6.34% material system at a higher Sc concentration of ScAlN/AlN/PCD at a high phase velocity of 7000 m s(-1), which could lead to the development of high-power durable wideband SAW device at high frequency.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Takanori Mimura, Reijiro Shimura, Akinori Tateyama, Yoshiko Nakamura, Takahisa Shiraishi, Hiroshi Funakubo
Summary: This study investigates the deposition of thin films using a no-heating method, and finds that some of these films exhibit ferroelectric and piezoelectric properties.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Akinori Tateyama, Yuichiro Orino, Yoshiharu Ito, Takahisa Shiraishi, Takao Shimizu, Minoru Kuribayashi Kurosawa, Hiroshi Funakubo
Summary: A setup and approach for simultaneous measurement of the inverse and direct transverse piezoelectric co-efficients of piezoelectric films was constructed. The measurements were carried out on a longitudinal vibration mode resonator with a hydrothermally synthesized (K,Na)NbO3 film deposited on a SrRuO3/SrTiO3 substrate. By applying a driving voltage to the actuator electrode, mechanical vibration was generated and measured using a laser Doppler vibrometer. The inverse and direct piezoelectric responses were evaluated by measuring the output current from the sensing electrode. The obtained coefficients were e31 = -3.60 C/m2 and e31 = -3.69 C/m2, respectively.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Chemistry, Physical
Kodai Aoyama, Takao Shimizu, Hideto Kuramochi, Masami Mesuda, Ryo Akiike, Takayoshi Katase, Yoshisato Kimura, Hiroshi Funakubo
Summary: The thermoelectric performance of SrSi2 composite films has been greatly improved by mixing the stable cubic phase with a metastable layered phase. By changing the deposition temperature, the phase fraction of the cubic and layered phases in SrSi2 films can be controlled. A film deposited at 700 degrees C, consisting of a semimetallic cubic phase and a small portion of a metallic layered phase, exhibits a high figure of merit, ZT, surpassing 0.4 at room temperature. This value is eight times larger than that of cubic SrSi2 bulk polycrystals previously reported. The improved performance is attributed to the microstructures of the films, which reduce thermal conductivity without sacrificing the power factor.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Takanori Mimura, Yuki Tashiro, Takao Shimizu, Hiroshi Funakubo
Summary: The effect of composition on the ferroelectric properties was studied using epitaxial x%YO1.5-(100-x%)Hf1-yZryO2 films. The tetragonal phase near the phase boundaries with the orthorhombic or monoclinic phase exhibits ferroelectricity through a field-induced phase transition. The orthorhombic phase generated via this transition has a lower coercive field, which can be controlled by composition while maintaining the same remnant polarization value. These findings are significant for applications of low-voltage driven ferroelectric devices.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Physics, Applied
Taichi Murashita, Yuxian Hu, Yuma Takahashi, Reika Ota, Kazuki Okamoto, Hiroshi Funakubo
Summary: (1-x)(Bi,K)TiO3-xCaTiO(3) epitaxial films with x = 0-1.0 were grown on (100)( c )SrRuO3//(100)SrTiO3 substrates by hydrothermal method. The film composition region can be divided into three according to its crystal structure. The films in x = 0-0.12 (Region 1) and 0.60-1.0 (Region 3) consist of a single phase, while two phases coexist in the intermediate range of x = 0.18-0.43 (Region 2). Ferroelectricity and effective transverse piezoelectric coefficient, effective d (33), were observed in Regions 1 and 2.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Miki Nakahata, Kazuki Okamoto, Keisuke Ishihama, Tomoaki Yamada, Hiroshi Funakubo
Summary: (100)/(001)-oriented tetragonal Pb(Zr,Ti)O-3 films with different thicknesses were grown on (100)(c)SrRuO3//(100)Pt//(100)ZrO2//Si(100) substrates by pulsed laser deposition. Their ferroelectric and piezoelectric properties were investigated and the effective piezoelectric response was found to increase with the increasing film thickness, attributed to the decrease in the constraint imposed by the substrate.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Jose P. B. Silva, Ruben Alcala, Uygar E. Avci, Nick Barrett, Laura Begon-Lours, Mattias Borg, Seungyong Byun, Sou-Chi Chang, Sang-Wook Cheong, Duk-Hyun Choe, Jean Coignus, Veeresh Deshpande, Athanasios Dimoulas, Catherine Dubourdieu, Ignasi Fina, Hiroshi Funakubo, Laurent Grenouillet, Alexei Gruverman, Jinseong Heo, Michael Hoffmann, H. Alex Hsain, Fei-Ting Huang, Cheol Seong Hwang, Jorge Iniguez, Jacob L. Jones, Ilya V. Karpov, Alfred Kersch, Taegyu Kwon, Suzanne Lancaster, Maximilian Lederer, Younghwan Lee, Patrick D. Lomenzo, Lane W. Martin, Simon Martin, Shinji Migita, Thomas Mikolajick, Beatriz Noheda, Min Hyuk Park, Karin M. Rabe, Sayeef Salahuddin, Florencio Sanchez, Konrad Seidel, Takao Shimizu, Takahisa Shiraishi, Stefan Slesazeck, Akira Toriumi, Hiroshi Uchida, Bertrand Vilquin, Xianghan Xu, Kun Hee Ye, Uwe Schroeder
Summary: Ferroelectric hafnium and zirconium oxides have shown significant progress in ultralow-power electronic systems, but technical limitations still hinder their application. This article aims to provide a comprehensive overview of the current state, challenges, and prospects for the development of these materials, with the collaboration of experts from different fields.
Article
Physics, Applied
Shinnosuke Yasuoka, Ryoichi Mizutani, Reika Ota, Takahisa Shiraishi, Takao Shimizu, Kazuki Okamoto, Masato Uehara, Hiroshi Yamada, Morito Akiyama, Hiroshi Funakubo
Summary: In this study, the switching kinetics of a (001)-out-of-plane-oriented (Al0.8Sc0.2)N thin film were investigated as a function of temperature and frequency. The results showed that the film exhibited stable switching behavior at high temperatures and frequencies, making it suitable for high-frequency applications.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Kota Hasegawa, Takao Shimizu, Takeo Ohsawa, Isao Sakaguchi, Naoki Ohashi
Summary: Room temperature ferroelectricity was studied in unsubstituted AlN films to investigate the effect of cation substitution. AlN and (Al0.7Sc0.3)N films deposited on (111) 0.5 wt.% Nb-doped SrTiO3 showed different in-plane lattice alignments depending on the composition and deposition temperature. The AlN films deposited at 450 degrees C exhibited incomplete ferroelectric switching due to dielectric breakdown, while the (Al0.7Sc0.3)N films showed full polarization reversal. Low-temperature deposition at 250 degrees C enhanced the dielectric breakdown field and allowed for sufficient polarization switching at room temperature. The reduction in coercive field was primarily attributed to the alteration of crystal lattice anisotropy caused by Sc.
APPLIED PHYSICS LETTERS
(2023)
