Advanced Electronic Materials最新文献_第6页

2D ferroelectric AgInP2Se6 for Ultra‐Steep Slope Transistor with SS Below 10 mV Decade−1

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-22 DOI: 10.1002/aelm.202400685

Yujue Yang, Zihao Liu, Xueting Liu, Huafeng Dong, Xin Zhang, Juehan Yang, Fugen Wu, Jingbo Li, Nengjie Huo

{"title":"2D ferroelectric AgInP2Se6 for Ultra‐Steep Slope Transistor with SS Below 10 mV Decade−1","authors":"Yujue Yang, Zihao Liu, Xueting Liu, Huafeng Dong, Xin Zhang, Juehan Yang, Fugen Wu, Jingbo Li, Nengjie Huo","doi":"10.1002/aelm.202400685","DOIUrl":"https://doi.org/10.1002/aelm.202400685","url":null,"abstract":"Along with continuous size shrinking, conventional silicon based transistors face the the challenges of both manufacture complexity and physical limitations. The negative capacitance transistors (NC‐FETs) using 2D ferroelectric materials as dielectric insulators are emerging as reliable solutions owing to their advantages of breaking the Boltzmann limitation and Complementary Metal‐Oxide Semiconductor (CMOS) compatibility. Here, the room temperature ferroelectricity of 2D AgInP2Se6 is discovered which is further integrated with MoS2 channel into ultra‐steep NC‐FETs for low‐power electronic applications. Due to the negative capacitance effect of AgInP2Se6 during the polarization reversal process, the transistor breaks the Boltzmann limitation with a subthreshold swing (SS) of less than 10 mV decade−1. By optimizing the thickness of AgInP2Se6, superior transistor performance with a minimum SS of 7.75 mV dec−1 and a high on/off ratio of up to 5.88 × 104 can be achieved. This work develops a new 2D ferroelectric AgInP2Se6 with room temperature ferroelectricity, providing promising material platforms for small‐size, ultra‐steep, and low‐power electronics.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"81 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Strain‐Induced Reduction of Centrosymmetry in Rare‐Earth Iron Garnet Thin Films

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-22 DOI: 10.1002/aelm.202400735

EMK Ikball Ahamed, Hiroyasu Yamahara, Md Shamim Sarker, Haining Li, Kazuo Morikawa, Kohei Yamagami, Masaki Kobayashi, Munetoshi Seki, Hitoshi Tabata

{"title":"Strain‐Induced Reduction of Centrosymmetry in Rare‐Earth Iron Garnet Thin Films","authors":"EMK Ikball Ahamed, Hiroyasu Yamahara, Md Shamim Sarker, Haining Li, Kazuo Morikawa, Kohei Yamagami, Masaki Kobayashi, Munetoshi Seki, Hitoshi Tabata","doi":"10.1002/aelm.202400735","DOIUrl":"https://doi.org/10.1002/aelm.202400735","url":null,"abstract":"Rare‐earth iron garnets (RIG, R3Fe5O12) are insulating ferrimagnets with high inversion symmetry because of their centrosymmetric cubic crystal structure. However, this high centrosymmetry can be reduced by introducing a non‐uniform strain, leading to a tetragonally distorted lattice structure. In this study, the strain‐induced lattice distortions and symmetry‐breaking features are investigated in compressively strained Sm3Fe5O12 and tensile‐strained Lu3Fe5O12 thin films around critical thicknesses. Experiments indicate that tensile strain prevents the in‐plane epitaxy from relaxing, whereas compressive strain leads to easy relaxation after reaching a critical threshold triggered by misfit dislocations. A non‐zero orbital moment, a more than tenfold increase in coercivity, and an increase in Gilbert damping near the critical thickness indicate a reduction of spatial inversion symmetry without forming any misfit dislocations. It is speculated that strain energy in uniformly strained epitaxial thin films has been partially released when the thickness reached about the critical thickness. The proposed strain‐mediated reduction of centrosymmetry may pave the way to achieve controllable magneto‐dynamics in dislocation‐free tensile strained RIG thin films.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"50 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Toward High‐Performance Electrochemical Energy Storage Systems: A Case Study on Predicting Electrochemical Properties and Inverse Material Design of MXene‐Based Electrode Materials with Automated Machine Learning (AutoML)

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-22 DOI: 10.1002/aelm.202400818

Berna Alemdag, Görkem Saygili, Matthias Franzreb, Gözde Kabay

{"title":"Toward High‐Performance Electrochemical Energy Storage Systems: A Case Study on Predicting Electrochemical Properties and Inverse Material Design of MXene‐Based Electrode Materials with Automated Machine Learning (AutoML)","authors":"Berna Alemdag, Görkem Saygili, Matthias Franzreb, Gözde Kabay","doi":"10.1002/aelm.202400818","DOIUrl":"https://doi.org/10.1002/aelm.202400818","url":null,"abstract":"This study highlights the potential of Automated Machine Learning (AutoML) to improve and accelerate the optimization and synthesis processes and facilitate the discovery of materials. Using a Density Functional Theory (DFT)‐simulated dataset of monolayer MXene‐based electrodes, AutoML assesses 20 regression models to predict key electrochemical and structural properties, including intercalation voltage, theoretical capacity, and lattice parameters. The CatBoost regressor achieves R2 values of 0.81 for intercalation voltage, 0.995 for theoretical capacity as well as 0.807 and 0.997 for intercalated and non‐intercalated in‐plane lattice constants, respectively. Feature importance analyses reveal essential structure‐property relationships, improving model interpretability. AutoML's classification module also bolsters inverse material design, effectively identifying promising compositions, such as Mg2+‐intercalated and oxygen‐terminated ScC2 MXenes, for high‐capacity and high‐voltage energy storage applications. This approach diminishes reliance on computational expertise by automating model selection, hyperparameter tuning, and performance evaluation. While MXene‐based electrodes serve as a demonstrative system, the methodology and workflow can extend to other material systems, including perovskites and conductive polymers. Future efforts should prioritize integrating AutoML with real‐time experimental feedback and hybrid simulation frameworks to create adaptive systems. These systems can iteratively refine predictions and optimize trade‐offs among critical metrics like capacity, stability, and charge/discharge rates, driving advancements in energy storage and other material applications.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"25 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

All Organic Fully Integrated Neuromorphic Crossbar Array 全有机全集成神经形态交叉阵列

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-22 DOI: 10.1002/aelm.202500054

Setareh Kazemzadeh, Tim Stevens, Yoeri van de Burgt

引用次数: 0

Ohmic Response in BiFeO3 Domain Walls by Submicron‐Scale Four‐Point Probe Resistance Measurements

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-21 DOI: 10.1002/aelm.202400794

Jan L. Rieck, Marcel L. Kolster, Romar A. Avila, Mian Li, Guus Rijnders, Gertjan Koster, Thom Palstra, Roeland Huijink, Beatriz Noheda

{"title":"Ohmic Response in BiFeO3 Domain Walls by Submicron‐Scale Four‐Point Probe Resistance Measurements","authors":"Jan L. Rieck, Marcel L. Kolster, Romar A. Avila, Mian Li, Guus Rijnders, Gertjan Koster, Thom Palstra, Roeland Huijink, Beatriz Noheda","doi":"10.1002/aelm.202400794","DOIUrl":"https://doi.org/10.1002/aelm.202400794","url":null,"abstract":"Conducting domain walls (DWs) hold promise for novel electronic devices. However, the electrical characterization of DWs is challenging because of their nanoscale dimensions and the large driving fields that are typically required due to the high resistance of the hosting material. Until now, lateral transport measurements of DWs have mainly been realized using lateral nano‐gap electrode structures or conventional conducting atomic force microscopy (cAFM). Here, a non‐destructive and lithography‐free method is reported for lateral transport measurement of DWs, which is applied to BiFeO3 (BFO) thin films utilizing a submicron‐scale multi‐point probe (MPP). Using different sets of individually biased probe tips, two‐ and four‐point measurements can be conducted over various lateral distances with a minimum tip spacing of several hundreds of nanometers. These measurements reveal the ohmic behavior of ferroelastic/ferroelectric 71° DWs in BFO thin films and the first collinear four‐point resistivity value of a single DW (free of lead and contact resistances). These findings contribute to a better understanding of DW conduction, highlighting the capability of MPPs for lateral transport measurements of materials containing conducting or even memristive nanoscale networks.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"17 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Solution‐Processed Bismuth Oxide Iodide/Organic‐Semiconductor Heterojunction for UV–vis‐NIR Photoresponsive Electronics

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-19 DOI: 10.1002/aelm.202400726

Preetam Dacha, Vaidehi Lapalikar, Anju Kumari Rohitlal, Mike Hambsch, Michael Ruck, Stefan C. B. Mannsfeld

{"title":"Solution‐Processed Bismuth Oxide Iodide/Organic‐Semiconductor Heterojunction for UV–vis‐NIR Photoresponsive Electronics","authors":"Preetam Dacha, Vaidehi Lapalikar, Anju Kumari Rohitlal, Mike Hambsch, Michael Ruck, Stefan C. B. Mannsfeld","doi":"10.1002/aelm.202400726","DOIUrl":"https://doi.org/10.1002/aelm.202400726","url":null,"abstract":"The emerging light absorber material bismuth oxide iodide BiOI, possesses convenient solution processibility and excellent chemical stability under ambient conditions along with a high light absorption coefficient reaching 5·104 cm−1. Classified as “defect‐tolerant,” BiOI is considered a green and low‐cost alternative to lead‐halide perovskites in optoelectronic devices. Its investigation in photoresponsive electronic devices, however, is limited due to its anisotropic carrier mobility and unique morphology in thin films. To utilize the advantageous properties of BiOI, in this work, it is integrated into a phototransistor as a bilayer heterojunction with the organic semiconductor DPPDTT. The smooth interfaces and higher carrier mobility of DPPDTT compared to BiOI and its hydrophobic nature enable their synergistic hybridization in a heterojunction that is optically active from the UV to the NIR region. The unencapsulated heterojunction phototransistors are stable for at least three months under atmospheric conditions. They show a high Ilight/Idark current ratio of over 104 at only 0.7 mW·cm−2 irradiation intensity at all investigated wavelengths, and a specific detectivity up to 5·1012 Jones. Initial synaptic measurements additionally reveal a neuromorphic behavior in the devices. This work charts a course towards the realization of cost‐effective high‐performance photoresponsive electronics for diverse applications.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"17 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reconfigurable Mixed‐Dimensional Transistor With Semimetal CNT Contacts

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-17 DOI: 10.1002/aelm.202400782

Xuanzhang Li, Yuheng Li, Zhen Mei, Liang Liang, Qunqing Li, Shoushan Fan, Yang Wei

{"title":"Reconfigurable Mixed‐Dimensional Transistor With Semimetal CNT Contacts","authors":"Xuanzhang Li, Yuheng Li, Zhen Mei, Liang Liang, Qunqing Li, Shoushan Fan, Yang Wei","doi":"10.1002/aelm.202400782","DOIUrl":"https://doi.org/10.1002/aelm.202400782","url":null,"abstract":"Reconfigurable low‐dimensional devices are attractive for electronics in the post‐Moore era. However, their performance and function design are limited by the metal–semiconductor contacts for the Fermi level pinning and fixed Schottky barrier height (SBH). Here, semimetal carbon nanotube (sCNT) contacts are incorporated into a WSe2 transistor to address these issues. The transistor exhibits excellent ambipolar transfer characteristics with on/off ratio exceeding 107 for both hole and electron conduction. Furthermore, the output characteristics are reconfigured among the four equivalent modes, P–P, P–N, N–P, and N–N, by applying appropriate gate voltage. The significant forward and backward rectifying behaviors at P‐N and N‐P modes are highly symmetrical and have high rectification ratios of over 106. The improvements are attributed to specific semimetal contacts for the gate‐tunable SBH and the drain‐induced Schottky barrier lowering (DISBL) effect. Practical circuits include a reconfigurable filter circuit and a logic invertor have been further demonstrated successfully. The progress reveals that the semimetal contacts have great potential in future reconfigurable devices and circuits.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"41 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ferroelectric Compensation Effect of the Hard Electrode for the HfO2-ZrO2 Superlattice Films at the Low-Annealing Temperature

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-17 DOI: 10.1002/aelm.202400830

Chuqian Zhu, Na Bai, Yufan Wang, Huajun Sun, Lanqing Zou, Yunhui Yi, Jiyang Xu, Jiawang Ren, Junming Zhang, Sheng Hu, Kanhao Xue, Lei Ye, Weiming Cheng, Qiang He, Xiangshui Miao

{"title":"Ferroelectric Compensation Effect of the Hard Electrode for the HfO2-ZrO2 Superlattice Films at the Low-Annealing Temperature","authors":"Chuqian Zhu, Na Bai, Yufan Wang, Huajun Sun, Lanqing Zou, Yunhui Yi, Jiyang Xu, Jiawang Ren, Junming Zhang, Sheng Hu, Kanhao Xue, Lei Ye, Weiming Cheng, Qiang He, Xiangshui Miao","doi":"10.1002/aelm.202400830","DOIUrl":"https://doi.org/10.1002/aelm.202400830","url":null,"abstract":"This study investigates the ferroelectric (FE) performance of [HfO2/ZrO2]6 superlattice FE capacitors using different top electrodes (TE). The unidirectional rapid thermal annealing (RTA) process from 450 to 600 °C is conducted. The device's remanent polarization (Pr) improved with TE hardness, and is maintained with harder TE at lower temperature. Furthermore, the superlattice's endurance and the recovery feature improve with harder TE. The increased orthorhombic phase (o-phase) content and the decreased tetragonal phase (t-phase) content indicate that the hard TE's out-of-plane stress at the interface suppressed the phase transition from the t-phase to the monoclinic phase (m-phase) and promotes the o-phase formation. It's known that hard electrodes usually have low coefficient of thermal expansion (CTE), which can generate high in-plane tensile strain optimizing the FE properties, so the lower-CTE electrodes devices’ FE performances are expected to degrade more with temperature decreasing, which is opposite with the experimental results. Therefore, hard electrodes can generate high out-of-plane compressive stress to offset the reduced in-plane tensile stress, leading to a FE compensation effect in low temperature thermal process.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"23 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Combinatorial Optimization and Large‐Scale Integration of Organic, Low‐Energy, and Fully‐Printed Flexible Ribbon Photosensors

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-15 DOI: 10.1002/aelm.202400657

Georgios Bairaktaris, Yudai Hemmi, Ryota Kobayashi, Yuki Hommura, Eva Bestelink, Hiroyuki Matsui, Radu A. Sporea

{"title":"Combinatorial Optimization and Large‐Scale Integration of Organic, Low‐Energy, and Fully‐Printed Flexible Ribbon Photosensors","authors":"Georgios Bairaktaris, Yudai Hemmi, Ryota Kobayashi, Yuki Hommura, Eva Bestelink, Hiroyuki Matsui, Radu A. Sporea","doi":"10.1002/aelm.202400657","DOIUrl":"https://doi.org/10.1002/aelm.202400657","url":null,"abstract":"The development and optimization of flexible electronics has allowed technology to be better integrated in applications and environments where the physically rigid nature of electronics is previously a limiting factor. Printing techniques contribute to lowering the fabrication costs and making manufacturing‐on‐demand viable. The use of flexible electronics in the user interface domain has been previously explored with solution‐processed optical photodetectors created and the feasibility of using flexible sensors demonstrated in augmented paper applications. In this work, low‐cost photodetectors are developed using scalable printing techniques, their electrical performance is analyzed, and their stability over time is studied both in air and in vacuum, the structure is optimized through a combinatorial optimization experiment, and a scalable integration method is demonstrated for creating larger, addressable arrays of detectors. This is a demonstration of how printing methods allow for easy, cost‐effective, and low‐energy manufacturing of uniform and stable photosensors.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"132 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Noise Spectroscopy and Electrical Transport In NbO2 Memristors with Dual Resistive Switching

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-02-14 DOI: 10.1002/aelm.202400877

Nitin Kumar, Jong E. Han, Karsten Beckmann, Nathaniel Cady, G. Sambandamurthy

{"title":"Noise Spectroscopy and Electrical Transport In NbO2 Memristors with Dual Resistive Switching","authors":"Nitin Kumar, Jong E. Han, Karsten Beckmann, Nathaniel Cady, G. Sambandamurthy","doi":"10.1002/aelm.202400877","DOIUrl":"https://doi.org/10.1002/aelm.202400877","url":null,"abstract":"Negative differential resistance (NDR) behavior observed in several transition metal oxides is crucial for developing next‐generation memory devices and neuromorphic computing systems. NbO2‐based memristors exhibit two regions of NDR at room temperature, making them promising candidates for such applications. Despite this potential, the physical mechanisms behind the onset and the ability to engineer these NDR regions remain unclear, hindering further development of these devices for applications. This study employed electrical transport and ultra‐low frequency noise spectroscopy measurements to investigate two distinct NDR phenomena in nanoscale thin films of NbO2. By analyzing the residual current fluctuations as a function of time, spatially inhomogeneous and non‐linear conduction are found near NDR‐1 and a two‐state switching near NDR‐2, leading to an insulator‐to‐metal (IMT) transition. The power spectral density of the residual fluctuations exhibits significantly elevated noise magnitudes around both NDR regions, providing insights into physical mechanisms and device size scaling for electronic applications. A simple theoretical model, based on the dimerization of correlated insulators, offers a comprehensive explanation of observed transport and noise behaviors near NDRs, affirming the presence of non‐linear conduction followed by an IMT connecting macroscopic device response to transport signatures at the atomic level.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"15 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0