Journal of Materials Chemistry C最新文献

{"title":"The effect of machining-generated residual stress on the properties of single crystal piezoelectric layers in high-frequency ultrasonic transducers†","authors":"Cong Luo, Chaorui Qiu, Yang Li, Mingwen Wang, Yi Quan and Zhuo Xu","doi":"10.1039/D5TC00779H","DOIUrl":"https://doi.org/10.1039/D5TC00779H","url":null,"abstract":"<p >During the mechanical thinning process for preparing ultrathin (approximately 100 μm) piezoelectric single crystals (SC) for high-frequency ultrasonic transducers, a significant degradation in performance has been observed in Pb(In<small>_1/2</small>Nb<small>_1/2</small>)O<small>₃</small>–Pb(Mg<small>_1/3</small>Nb<small>_2/3</small>)O<small>₃</small>–PbTiO<small>₃</small> (PIN–PMN–PT) SC sheets. Experimental results indicate that this degradation is primarily due to machining-generated residual stress during the thinning process. Upon the removal of mechanical force, residual stress is induced within the PIN–PMN–PT SC sheet, leading to a decline in the dielectric, piezoelectric, and electromechanical properties. The residual stress significantly impacts both external surface roughness and internal domain structure of the SC sheet, directly affecting its electrical performance. Additionally, the residual stress exacerbates electrical fatigue in the PIN–PMN–PT SC sheet during practical use. To address these issues, high-temperature annealing following mechanical thinning has been demonstrated to effectively eliminate or minimize residual stress, thereby substantially mitigating its adverse effects. This process enhances the electrical properties, thermal stability, and resistance to electrical fatigue of the SC sheet. This study offers insights into optimizing the performance optimization of high-performance SC sheets for improving the performance of high-frequency transducers.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9483-9493"},"PeriodicalIF":5.7,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073561","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}

{"title":"Design principles of electroluminescent devices based on different electrodes and recent advances toward their application in textiles","authors":"Qiyuan Xie, Yijun Yao, Lei Wu, Ying Xue, Guodong Shen, Changsheng Guo, Bin Du, Hailiang Wu and Yang Jin","doi":"10.1039/D5TC00209E","DOIUrl":"https://doi.org/10.1039/D5TC00209E","url":null,"abstract":"<p >Alternating current electroluminescent (ACEL) devices have become an important direction for the development of visualized smart wearable e-textiles due to their advantages of light weight, flexibility, easy integration, and convenient processing. The electrode layer is a crucial component of ACEL devices, providing the necessary electric field for the dielectric and luminescent layers, and facilitating the stable transport and recombination of electrons and holes in the luminescent layer. Herein, the structural design principles and luminescence mechanisms of ACEL are reviewed, and the newest research and remarkable results of metal-, carbon-, and ion-gel-based electrodes are introduced. This review emphasizes that optimizing the conductive pathways of electrodes, enhancing the interfacial roles of functional layers, and adjusting the thickness and microstructure of layers are crucial for developing high-brightness and stable ACEL devices. Also, increasing the electric field strength and selecting high dielectric constants are identified as key factors. On this basis, the recent progress of ACEL fibers, films, and fabrics in textiles is highlighted. Finally, the challenges and growth encountered in the development of ACEL devices are prospected, considering aspects such as voltage, luminous brightness, color, sensitivity, comfort, and large-scale processing.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 18","pages":" 8934-8957"},"PeriodicalIF":5.7,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925372","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}

{"title":"Development of self-powered multicolored smart windows utilizing viologen derivatives†","authors":"Wanxiong Yong, Weining Liu, Xiaoying Xin and Guodong Fu","doi":"10.1039/D5TC00818B","DOIUrl":"https://doi.org/10.1039/D5TC00818B","url":null,"abstract":"<p >In recent years, smart windows that provide energy-efficient solutions for the construction and transportation sectors have attracted considerable interest as a result of increasingly severe environmental issues. Electrochromic windows have emerged as a prominent option because of their high coloring efficiency and broad optical modulation range. However, traditional electrochromic devices necessitate the use of an external electric field to operate, which not only increases energy consumption but also poses safety risks. In this study, we propose a novel self-powered electrochromic smart window that utilizes the principles of self-charging batteries to achieve optical modulation across a wide spectrum of visible light. This device utilizes viologen derivatives as electrochromic materials due to their highly reversible redox reactions and the ease with which their colors can be manipulated. The devices can exhibit three distinct display states, transitioning from colorless or pale yellow to blue, purple, and green, by varying the types of viologen derivative electrochromic materials employed. Notably, simply disconnecting the zinc anode from the conductive glass cathode enables the self-recovery of the electrochromic state, thereby restoring the initial transmittance level. This recovery takes place as the viologen cation radical spontaneously oxidizes to form the divalent ion; a process facilitated by oxygen dissolved within the gel electrolyte. The device not only features a multicolor display and efficient optical modulation but also demonstrates excellent cycle stability and safety. Consequently, the smart window presented functions as a multifunctional device, serving both as an electrochromic window and an energy storage unit. This innovative self-powered multicolor display device significantly broadens the application scope of electrochromic smart windows. It achieves not only the shading effect of optical modulation but also meets the energy-saving and flexible design needs in the fields of architecture and transportation, thereby providing opportunities for further applications in the new energy industry.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9474-9482"},"PeriodicalIF":5.7,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073560","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}

{"title":"Coexistence of large positive and negative electrocaloric effects near room temperature in a Pb1−x(Li,La)xZrO3/Ca3Mn2O7 heterojunction†","authors":"Wenyue Zhao, Zhao Wang, Yazhou Peng, Lei Shi, Wenjing Hua, Xiaoxia Yang, Jie Wang, Weidong Fei and Yu Zhao","doi":"10.1039/D4TC04955A","DOIUrl":"https://doi.org/10.1039/D4TC04955A","url":null,"abstract":"<p >Electrocaloric refrigeration films have a very significant potential for application in the field of microelectronics. However, it is difficult for the refrigeration efficiency of a single positive/negative electrocaloric effect to match the demand, because it can only cool when the electric field is removed or applied. Herein, the coexistence of large positive and negative electrocaloric effects is obtained in a Pb<small>_{1−<em>x</em>}</small>(Li<small>_0.5</small>La<small>_0.5</small>)<small>_<em>x</em></small>ZrO<small>₂</small>/Ca<small>₃</small>Mn<small>₂</small>O<small>₇</small> (PLLZ/CMO) heterojunction near room temperature. The built-in electric field is induced in the heterojunction region, and it can regulate the phase structure of the PLLZ layer in the heterojunction region with the help of the external electric field. In addition, Li<small>⁺</small>–La<small>³⁺</small> doping suppresses the phase transition of the PLLZ layer, and thus the change in the sign of the temperature is regulated by the external electric field. The adiabatic temperature changes of the PLLZ/CMO bilayer film with <em>x</em> = 0.4 at 303 K are 33 K at 550 kV cm<small>⁻¹</small> and −1.54 K at 140 kV cm<small>⁻¹</small>. The large positive and negative temperature changes regulated by the voltage indicate a reliable technique for practical production.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9888-9895"},"PeriodicalIF":5.7,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073543","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}

{"title":"Circularly polarized luminescence signals of photoresponsive liquid crystals and their applications","authors":"Shengwen Bao, Shan Li, Ziran Tang, Yunhui Wan, Guoquan Zhou, Zehui Yang, Deli Sun, Danfeng Ye and Liangliang Zhu","doi":"10.1039/D5TC01181G","DOIUrl":"https://doi.org/10.1039/D5TC01181G","url":null,"abstract":"<p >Photoresponsive liquid crystals have attracted much research attention due to their advantages of precision and non-contact regulation, among which the circularly polarized luminescence (CPL) properties have become a focal point in the field of liquid crystal research. Although photoluminescent crystals and CPL materials have been individually reviewed, there is a lack of a systematic review that comprehensively summarizes photoresponsive liquid crystal CPL and its mechanisms, influencing factors and applications. In order to study these molecules and their importance in scientific research in more depth, this paper reviews the research progress of photo responsive liquid crystal CPL, clarifies the interaction relationship between photo regulation and liquid crystal CPL, analyses the influence of doping ratios on their performance, and discusses advanced applications based on liquid crystal CPL. In addition, this paper highlights the importance of regulating the helical structure of liquid crystal systems by means of photos and the related mechanisms, and provides an outlook on the future development of this field.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9453-9464"},"PeriodicalIF":5.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073557","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}

{"title":"Interpretable and uncertainty-informed machine learning to accelerate the design and discovery of lead-free piezoceramics with large piezoelectric constant†","authors":"Heng Hu, Bin Wang, Didi Zhang, Kang Yan, Tao Tan and Dawei Wu","doi":"10.1039/D5TC00865D","DOIUrl":"https://doi.org/10.1039/D5TC00865D","url":null,"abstract":"<p >Potassium sodium niobate (KNN)-based ceramics are promising alternatives to lead-containing piezoelectric materials. However, the vast design space, characterized by multiple dopant choices and variable content, presents a considerable challenge in the chemical modification of KNN compositions to improve their piezoelectric performance. In recent years, the rapid advance of machine learning (ML) techniques has facilitated expedited materials design and discovery with deeply sought insights into the materials. In this study, we constructed an interpretable and uncertainty-informed ML framework to optimize the piezoelectric coefficient <em>d</em><small>₃₃</small> of a KNN-based lead-free system. We identified and analyzed the influential features for the <em>d</em><small>₃₃</small> prediction and conducted three experimental iterations based on the uncertainty-informed predictions obtained from the Monte Carlo dropout (MCDropout). Promising KNN compositions exhibiting large <em>d</em><small>₃₃</small> values over 300 pC N<small>⁻¹</small> were located and synthesized. Furthermore, the MCDropout markedly reduced the computational cost by 33% compared to the commonly used bootstrap method for uncertainty assessment. This study exhibits an ML framework with enhanced interpretability and search efficiency for optimizing the crucial piezoelectric properties of piezoceramics. The application scope of the utilized methods can be extended to various materials with tailored properties.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 18","pages":" 8958-8968"},"PeriodicalIF":5.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925373","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}

{"title":"Far-red emitting phosphors for plant growth applications: fitted and enhanced via cation substitution of Gd3+†","authors":"Chunli Peng, Jueran Cao, Baoling Tang, Tianrui Li, Mingkai Wei, Haoran Zhang, Xuejie Zhang, Mingtao Zheng, Maxim S. Molokeev and Bingfu Lei","doi":"10.1039/D5TC00678C","DOIUrl":"https://doi.org/10.1039/D5TC00678C","url":null,"abstract":"<p >Far-red (FR) light is involved in plant photomorphogenesis as a light signal. To realize the match between the absorption peak (730 nm) of a plant photosensitive pigment (Pfr) and the emission spectrum (708 nm) of a Y<small>₃</small>Ga<small>_4.87</small>O<small>₁₂</small>:0.13Cr<small>³⁺</small> (YGO:0.13Cr<small>³⁺</small>) phosphor, in this study, we employed an ‘A site modification-B site response’ crystal-field-modulation strategy using the garnet structure Y<small>₃</small>Ga<small>₅</small>O<small>₁₂</small>, where doping large radius Gd<small>³⁺</small> at the A site induced [YO<small>₈</small>] polyhedral expansion and triggered [GaO<small>₆</small>] octahedral distortion, thereby weakening the crystal field strength to achieve a red shift in the spectrum. The optimized Gd<small>_1.2</small>Y<small>_1.8</small>Ga<small>_4.87</small>O<small>₁₂</small>:0.13Cr<small>³⁺</small> (GYGO:0.13Cr<small>³⁺</small>) phosphor exhibited high external quantum efficiency (34%) and excellent thermal stability (85.5% intensity at 423 K) under 450 nm excitation. Its emission peak at 726 nm was significantly close to 730 nm, while its luminescence intensity was improved by 141% that of the original system. It was successfully fabricated as an FR pc-LED device, achieving a 36.86 mW output power and 13.5% photoelectric efficiency at 100 mA current. Lettuce growth experiments showed that the device enhanced biomass production by 30% through precise spectral adaptation. The present work can promote the leap in plant lighting from rough supplementation to spectral customization through the whole chain of structural aberration–photoelectricity–biological effects.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9747-9755"},"PeriodicalIF":5.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073524","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}

{"title":"Magnetic properties and dipolar interactions of Fe3O4 nanoparticle clusters produced by bottom-up self-assembly","authors":"Fernando Fabris, Adriele A. Almeida, Pablo Rafael Trajano Ribeiro, Kleber Roberto Pirota and Diego Muraca","doi":"10.1039/D5TC00022J","DOIUrl":"https://doi.org/10.1039/D5TC00022J","url":null,"abstract":"<p >Magnetic nanoparticles (MNPs) exhibit unique magnetic behaviors that make them highly applicable in various fields such as biomedical technology, energy, and sensing. This study investigates the magnetic properties and dipolar interactions of Fe<small>₃</small>O<small>₄</small> nanoparticle clusters with different average sizes (27.4 nm, 79.2 nm, and 112.9 nm) produced by an emulsion-based bottom-up self-assembly process. The MNPs, with an individual size of 9.8 nm, were organized into clusters, and their collective magnetic properties were explored using detailed DC and AC magnetic studies. We applied a phenomenological mean-field model to describe the magnetic behavior of the clusters, including an increase in blocking temperature, energy barriers, and relaxation dynamics as a function of cluster size. The results indicate a significant influence of dipolar interactions on the energy barriers and magnetic moment dynamics, with larger clusters exhibiting stronger dipolar fields. Our findings provide insights into the interaction between nanoparticle arrangement and magnetic properties, which offers potential for the development of novel magnetic materials for advanced applications.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9756-9767"},"PeriodicalIF":5.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073525","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}

{"title":"Giant thermally induced band-gap renormalization in anharmonic silver chalcohalide antiperovskites.","authors":"Pol Benítez, Siyu Chen, Ruoshi Jiang, Cibrán López, Josep-Lluís Tamarit, Jorge Íñiguez-González, Edgardo Saucedo, Bartomeu Monserrat, Claudio Cazorla","doi":"10.1039/d5tc00863h","DOIUrl":"https://doi.org/10.1039/d5tc00863h","url":null,"abstract":"<p><p>Silver chalcohalide antiperovskites (CAP), Ag₃XY (X = S, Se; Y = Br, I), are a family of highly anharmonic inorganic compounds with great potential for energy applications. However, a substantial and unresolved discrepancy exists between the optoelectronic properties predicted by theoretical first-principles methods and those measured experimentally at room temperature, hindering the fundamental understanding and rational engineering of CAP. In this work, we employ density functional theory, tight-binding calculations, and anharmonic Fröhlich theory to investigate the optoelectronic properties of CAP at finite temperatures. Near room temperature, we observe a giant band-gap (<i>E</i> _g) reduction of approximately 20-60% relative to the value calculated at <i>T</i> = 0 K, bringing the estimated <i>E</i> _g into excellent agreement with experimental measurements. This relative <i>T</i>-induced band-gap renormalization is roughly twice the largest value previously reported in the literature for similar temperature ranges. Low-energy optical polar phonon modes, which break inversion symmetry and enhance the overlap between silver and chalcogen s electronic orbitals in the conduction band, are identified as the primary drivers of this significant <i>E</i> _g reduction. Furthermore, when temperature effects are considered, the optical absorption coefficient of CAP increases by nearly an order of magnitude in the visible light spectrum. These findings not only bridge a critical gap between theory and experiment but also pave the way for future technologies where temperature, electric fields, and light dynamically modulate optoelectronic properties, establishing CAP as a versatile platform for energy and photonic applications.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" ","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12035675/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upconversion phosphors of CaLaAl3O7:RE3+/Yb3+ (RE = Tm, Ho) and their multifunctional applications for multi-color anti-counterfeiting and laser displays†","authors":"Shanshan Zhao, Hehe Dong, Weichang Li, Lei Zhang, Shikai Wang, Chunlei Yu and Lili Hu","doi":"10.1039/D5TC00012B","DOIUrl":"https://doi.org/10.1039/D5TC00012B","url":null,"abstract":"<p >Upconversion emission materials have many advantages, such as narrowband sharp line emission, excellent photochemical stability, and long lifespan. In particular, under 980 nm invisible laser-beam irradiation, materials with visible light upconversion luminescence have vital application value in optical anti-counterfeiting and laser displays. In this study, a library of upconversion phosphors of CaLaAl<small>₃</small>O<small>₇</small>:RE<small>³⁺</small>/Yb<small>³⁺</small> (RE = Tm, Ho) was produced through a high-temperature solid-state reaction method. The powders exhibited different color emissions at different excited wavelengths. Under 980 nm laser excitation, Tm<small>³⁺</small>/Yb<small>³⁺</small> co-doped phosphors exhibited an upconversion emission of 474 nm blue light, which was attributed to the <small>¹</small>G<small>₄</small> → <small>³</small>H<small>₆</small> transition of Tm<small>³⁺</small>, and the fitting slope of the upconversion luminescence intensity <em>vs.</em> laser-pump power density was <em>n</em><small>_450–500</small> = 2.83, which indicated the three-photon absorption upconversion process. Additionally, Ho<small>³⁺</small>/Yb<small>³⁺</small> co-doped phosphors had the strongest red emission at 660 nm, originating from the <small>⁵</small>F<small>₄</small>/<small>⁵</small>S<small>₂</small> → <small>⁵</small>I<small>₈</small> transition of Ho<small>³⁺</small>, which belongs to the two-photon absorption process. Subsequently, the changes in chromaticity coordinates of the prepared samples were analyzed under different light excitations, and different light color emissions were observed. The color purities of Ho<small>³⁺</small>/Yb<small>³⁺</small> and Tm<small>³⁺</small>/Yb<small>³⁺</small> co-doped samples were 99.9% and 65.4%, respectively. Finally, we verified the practical application value of the prepared powder in the fields of multi-color luminescence optical anti-counterfeiting and laser displays. The results show that the produced phosphors have vital application potential in information security protection, optical data storage, and 3D laser displays.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9875-9887"},"PeriodicalIF":5.7,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073542","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}