Applied Physics A最新文献

{"title":"Effect of Gd-doping on magnetic, ferroelectric, and optical properties of BiFeO3 multiferroic nanoparticles synthesized by Sol-gel route","authors":"Subhasmita Jena,&nbsp;Sovan Kumar Patra,&nbsp;Budhendra Singh,&nbsp;Amiya Priyam,&nbsp;Bhavya Bhushan","doi":"10.1007/s00339-025-08621-9","DOIUrl":"10.1007/s00339-025-08621-9","url":null,"abstract":"<div><p>Multiferroic nnanoparticles (NPs) of pristine BiFeO₃ (BFO) and Gd-doped BFO, Bi_1 − xGd_xFeO₃ (x = 0.01, 0.03, and 0.05) were synthesized by ethylene glycol-based sol-gel route. The impact of Gd-concentration on their structural, optical, ferroelectric, and magnetic characteristics has been examined. XRD confirmed the phase purity and, it was found that the rhombohedral distorted perovskite structure remained the same on Gd-doping. The average particle size, as determined by FE-SEM, decreased exponentially in the following manner, 46 → 44 → 42 → 41 nm for Gd-doping level varying as 0% → 1% → 3% → 5%, respectively. In Raman spectra of 5%-Gd-doped NPs, the phonon modes corresponding to A₁ ^− 3, A₁ ^− 4 and E peaks show a red shift of 2.6 cm^− 1, 2.5 cm^− 1, and 5.2 cm^− 1, respectively. Well-defined absorption peak at 459 nm was seen in UV-visible absorption spectra of BFO NPs which blue-shifted to 446 nm and the bandgap varied linearly with dopant concentration. 3% Gd-doping was found to be optimum as it caused more than 100% enhancement of the saturation and remanent magnetization, upto 0.702 emu/g and 0.057 emu/g, respectively. In ferroelectric measurements, all samples showed non-saturating P-E hysteresis curves, with pristine BFO having the maximum remnant polarization. These Gd-doped BFO NPs with enhanced magnetic and optical properties are well-suited for applications in photocatalysis and spintronics.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The study of the effect of device downsizing on 1/f noise in deep submicron magnetic tunnel junctions","authors":"T. N. Anh Nguyen,&nbsp;Q. N. Pham,&nbsp;K. T. Do,&nbsp;H. K. Vu,&nbsp;H. N. Pham,&nbsp;D. T. Tran,&nbsp;H. M. Do","doi":"10.1007/s00339-025-08630-8","DOIUrl":"10.1007/s00339-025-08630-8","url":null,"abstract":"<div><p>In this study, nanoscale MgO magnetic tunnel junctions (MTJs) with an orthogonal magnetization structure between the free and pinned layers and various junction sizes were fabricated, and their tunnel magnetoresistance (TMR) ratio, resistance-area (RA) product, and low-frequency noise (LFN) behavior were experimentally investigated thoroughly. The circular MTJs with various diameters (80–400 nm) show high TMR ratios of greater than 100% at room temperature (RT) with relatively low RA in the range of 2.8–4.4 Ωµm². We found that the noise power spectral density (PSD) as a function of d.c. bias voltage (<i>V</i>_bias) and perpendicular d.c. bias magnetic field (<i>H</i>_DC) in all junction sizes exhibits 1/<i>f</i>-noise behavior within a wide investigated frequency range from 5 Hz up to 10 kHz. The bias voltage and magnetic field-dependent LFN indicated that the 1/<i>f</i> noise of the MTJs has both electric and magnetic origins. The results show that though the TMR ratio and RA product are size-independent, the Hooge parameter for the parallel (P) state (<i>α</i>_P) is strongly dependent on the MTJ size, and its values decrease with decreasing MTJ size, suggesting the reduction of electronic 1/<i>f</i> noise as the MTJ size shrinks. This is the first experimental report on the size dependency of electronic 1/<i>f</i> noise in nano-sized MTJs. The results may open a new approach for reducing not only magnetic but also electronic 1/<i>f</i> noises in MTJs by downscaling, thereby increasing the sensitivity of MTJ nanosensors.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic analysis of Rayleigh waves in nonlocal porous orthotropic thermoelastic medium with diffusion","authors":"Abhishek Mallick,&nbsp;Siddhartha Biswas","doi":"10.1007/s00339-025-08607-7","DOIUrl":"10.1007/s00339-025-08607-7","url":null,"abstract":"<div><p>This research investigates the propagation of Rayleigh waves in an orthotropic medium containing voids, employing nonlocal elasticity and the three-phase lag (TPL) model. The presence of voids, nonlocal effects, and diffusion are critical factors that significantly influence the behavior of Rayleigh waves, which are crucial for various engineering applications and geophysical explorations. The orthotropic medium’s directional dependence on mechanical properties, combined with voids, adds complexity to the wave propagation dynamics. We utilize the TPL model to incorporate phase lags in heat conduction, mechanical deformation, and mass diffusion, providing a comprehensive framework for analyzing these interactions. Normal mode analysis is employed to derive the dispersion relations and study the effects of nonlocal elasticity on wave characteristics. The inclusion of nonlocal elasticity accounts for long-range interactions, enhancing the accuracy of the model in predicting wave behavior. Our findings reveal that the presence of voids, nonlocal elasticity, and diffusion significantly impact the propagation speed, attenuation coefficient, penetration depth, and specific loss of Rayleigh waves. The TPL model effectively captures the combined effects of these factors, showing that nonlocal elasticity introduces additional complexity and dispersion in wave propagation. Diffusion tends to smooth out the wave characteristics, while the presence of voids influences the propagation speed, attenuation coefficient, penetration depth, and specific loss. This study contributes to the development of more accurate predictive models for wave propagation in complex media, with implications for materials science, structural engineering, and geophysical exploration. The results highlight the necessity of considering voids, nonlocal elasticity, and diffusion when analyzing Rayleigh wave propagation in orthotropic media.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dopant-dependent spin–lattice coupling in La0.7Ca0.15Sr0.15MnO3: Fe/Co/Ni effects on magnetocaloric properties","authors":"Xiuxin Zheng,&nbsp;Lin Gong,&nbsp;Zhengguang Zou,&nbsp;Zhuojia Xie","doi":"10.1007/s00339-025-08622-8","DOIUrl":"10.1007/s00339-025-08622-8","url":null,"abstract":"<div><p>In this paper, La_0.7Sr_0.15Ca_0.15Mn_0.95A_0.05O₃ (A = Fe, Co and Ni) were fabricated via the sol–gel (S-G) approach. The samples are all rhombohedral structure shapes and belong to the trigonal space group R-3c, as shown by XRD. ZEISS Gemini SEM 300 scans showed irregular sub-micron particles with decreasing particle size for La_0.7Sr_0.15Ca_0.15Mn_0.95A_0.05O₃ (A = Fe, Co and Ni). The magnetic properties were characterized utilizing an MPMS, and the magnetocaloric effects (MCE) were further investigated. The investigations of La_0.7Sr_0.15Ca_0.15Mn_0.95A_0.05O₃ (A = Fe, Co and Ni) found that their Curie temperatures (Tc) were 289.5 K, 290.2 K, and 300 K, respectively. The maximum magnetic entropy change (<span>(-Delta {S}_{M}^{max})</span>) for La_0.7Sr_0.15Ca_0.15Mn_0.95A_0.05O₃ (A = Fe, Co and Ni) at 5 T is 5.107 J/(kg∙K), 4.177 J/(kg∙K) and 3.852 J/(kg∙K), and the relative cooling power (<i>RCP</i>) is 264.819 J/kg, 275.3409 J/kg and 288.7435 J/kg. The Arrott curve, normalization and Curie–Weiss law (CW) fit together to determine that the second-order ferromagnetic-to-paramagnetic (FM-to-PM) transition is observed in the three samples, along with a small magnetic hysteresis and thermal hysteresis, the super-exchange interactions (SE) and the double-exchange interactions (DE) competed with each other to increase half peak width and <i>RCP</i>, with La_0.7Sr_0.15Ca_0.15Mn_0.95A_0.05O₃ (A = Ni) having the largest <i>RCP</i>. While conventional low-temperature magnetic materials need to work in a liquid helium environment, room-temperature magnetic materials do not need to rely on extreme cooling conditions, which greatly reduces the cost of refrigeration equipment, and thus room-temperature magnetically cooled materials have a greater potential for research and development. In this paper, Ni is used as the doping element, and its <i>RCP</i> can reach 288.7435 J/kg, and its Tc is close to room temperature, so it is possible to be used as a room-temperature magnetic cooling material.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlling vortex matter via a superconducting nano-bridge sample","authors":"C. A. Aguirre,&nbsp;J. Faúndez,&nbsp;P. Díaz,&nbsp;D. Laroze,&nbsp;A. S. Mosquera,&nbsp;N. C. Costa,&nbsp;J. Barba-Ortega","doi":"10.1007/s00339-025-08644-2","DOIUrl":"10.1007/s00339-025-08644-2","url":null,"abstract":"<div><p>A fundamental understanding of superconducting nanodevices is required to develop emerging quantum technologies. We use time-dependent Ginzburg-Landau theory to investigate the magnetic response of a three-dimensional monolithic superconducting nano-bridge in the presence of two external magnetic fields. Our analysis focuses on the behavior of the Gibbs free energy density, magnetization, superconducting Cooper pair density, current flow as a function of geometry, external magnetic fields, and induced currents. In three distinct cases, we explore the interplay between geometry, induced current, and vortex dynamics. First, we analyze the stability of vortices under variations of the geometry without induced currents. Second, we examine the influence of induced currents (given by a second external magnetic field) on the left single boundary of the superconducting nano-bridge sample while keeping the geometric parameters fixed. Third, we introduce left and right-induced currents at the boundaries and investigate their impact on vortex nucleation. Our results demonstrate that the nano-bridge dimensions play a crucial role in stabilizing and controlling single-vortex states in the nano-bridge sample. We find that induced currents generate vortex motion within the superconducting nano-bridge sample, highlighting the intricate dependence of vortex dynamics on currents under geometrical constraints. Our findings provide valuable insights into controlled vortex manipulation in nano-scale superconductors, with potential applications in superconducting electronics and quantum technologies.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescent properties of Er3+-Eu3+ co-doped tellurite glass for white light LEDs","authors":"Qun Wang,&nbsp;Ranran Bu,&nbsp;Changyuan Xu,&nbsp;Fengjiao Zhao,&nbsp;Hongming Yin","doi":"10.1007/s00339-025-08629-1","DOIUrl":"10.1007/s00339-025-08629-1","url":null,"abstract":"<div><p>Tellurite glass samples doped with Er³⁺ and Eu³⁺ were synthesized by the high-temperature solid phase method. The XRD diffraction pattern shows the amorphous properties of the prepared samples. The luminescence properties of glass samples were analyzed using the absorption spectrum, excitation spectrum, and emission spectrum. The energy transfer mechanism between Er³⁺ ions and Eu³⁺ ions was studied by changing the concentration of Eu³⁺ ions, and the results were verified by measuring the luminescence decay lifetime. It is worth noting that at 380 nm excitation, Er³⁺ and Eu³⁺ co-doped tellurite glass exhibits remarkable tunable luminescence characteristics: by adjusting the concentration of Eu³⁺ ions, the emission color can be flexibly adjusted from green to orangish-red. In addition, by effectively combining the prepared co-doped glass sample with the 380 nm GaN chip, the cold white light emission with CIE coordinates of (0.324, 0.320) was successfully achieved. According to the variable-temperature spectroscopy, at 210℃, the emission peak intensities of the co-doped Er³⁺/Eu³⁺ tellurite glass at 547 nm and 613 nm are above 70% of the room-temperature luminescence intensity, demonstrating excellent thermal stability.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tuning the properties of Yb-Doped BiFeO3: insights into structural, electrical, magnetoelectric and photocatalytic behavior","authors":"Asif Nazir Ganie,&nbsp;Iqra Irshad,&nbsp;Mehraj ud Din Rather,&nbsp;Basharat Want","doi":"10.1007/s00339-025-08603-x","DOIUrl":"10.1007/s00339-025-08603-x","url":null,"abstract":"<div><p>The manipulation of electric properties by the magnetic field in magnetoelectric multiferroic materials has fuelled enormous research activity, to realise their potential for magnetoelectric devices. So, this report investigates the influence of ytterbium (Yb³⁺) substitution on the structural, magnetic, and magnetoelectric properties of hydrothermally synthesised bismuth ferrite Bi_1-xYb_xFeO₃ (<i>x</i> = 0.00, 0.20, 0.25, 0.30). Yb³⁺ doping successfully lowers the average grain size, while preserving a distorted rhombohedral structure, within the R3c space group. Notably, Yb-doped bismuth ferrite exhibits enhanced ferromagnetic behaviour, with the Bi_0.7Yb_0.3FeO₃ composition achieving a significant magnetization of 0.337 emu/g. Moreover, the addition of Yb³⁺ causes significant changes in electric polarisation, which significantly impacts the multiferroic properties. A high magnetoelectric coupling coefficient (15.049 mVcm⁻¹Oe⁻¹) for Bi_0.7Yb_0.3FeO₃, highlights its promise for applications in multifunctional devices, where the interplay between magnetic and electric order parameters is critical for advanced technological innovations. The photoluminescence analysis demonstrates a decline in intensity with increasing Yb³⁺ doping, suggesting a lower electron–hole recombination rate. The photocatalytic activity of the synthesized nanoparticles was assessed for methylene blue degradation under visible light exposure, with the 30% doped sample exhibiting the highest efficiency. These results indicate the potential of Yb-doped BiFeO₃ nanoparticles for wastewater treatment applications.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The codoping of Bi3+ to enhance the long afterglow performance of LiTaO3:Er3+","authors":"Lifang Yuan,&nbsp;Junzhong Wang,&nbsp;Zhijin Huang,&nbsp;Kaixiang Shen","doi":"10.1007/s00339-025-08616-6","DOIUrl":"10.1007/s00339-025-08616-6","url":null,"abstract":"<div><p>Long afterglow phosphors have garnered significant attention for their ability to emit light long after excitation ceases. Afterglow emission relies on metastable trap levels within the bandgap of the host materials. Effective trap engineering strategies to optimize traps are critical in determining the afterglow performance. In this study, we investigate the codoping of Bi³⁺ and Er³⁺ into LiTaO₃ to enhance afterglow performance. Through high-temperature solid-state synthesis, a series of LiTaO₃:x%Bi³⁺, y%Er³⁺ (x = 0 or 0.5%, y = 0.1–4.0%) samples were prepared successfully. Structural characterization confirmed the successful incorporation of Bi³⁺ and Er³⁺ into the Li⁺ sites without disrupting the host lattice. Photoluminescence studies revealed that Bi³⁺ codoping significantly enhances the green emission of Er³⁺, with optimal performance achieved at 1.0% Er³⁺ doping. Thermoluminescence (TL) analysis demonstrated the presence of traps with the depth of 0.748 eV, enabling prolonged afterglow emission at room temperature. The afterglow mechanism involves charge carrier storage in traps under UV excitation, followed by thermal release and recombination at luminescent centers, facilitated by energy transfer from Bi³⁺ to Er³⁺. This work provides a strategy for designing a long afterglow phosphor through controlled codoping, offering insights into trap engineering and energy transfer processes in perovskite-based luminescent materials.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction Note: Development of environmental friendly Mo-doped MnO2 via hydrothermal route for supercapacitor as pollution-free source of energy","authors":"F. F. Alharbi,&nbsp;Muhammad Abdullah,&nbsp;Salma Aman,&nbsp;Soumaya Gouadria,&nbsp;Asma Sadaf,&nbsp;Taha Abdel Mohaymen Taha,&nbsp;Hafiz Muhammad Tahir Farid","doi":"10.1007/s00339-025-08631-7","DOIUrl":"10.1007/s00339-025-08631-7","url":null,"abstract":"","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The evidence of samarium substitution defect contributing to local structural-polar heterogeneity and Tc in Sm-doped 0.68PMN-0.32PT ceramics compensated by B-site vacancies","authors":"Jing Yang,&nbsp;Wenjun Wang,&nbsp;Yan Li,&nbsp;Shaorong Feng,&nbsp;Tao Zhang,&nbsp;Xuping Niu,&nbsp;Min Li,&nbsp;Li’An Han,&nbsp;Xingzhong Cao,&nbsp;Runsheng Yu,&nbsp;Baoyi Wang","doi":"10.1007/s00339-025-08552-5","DOIUrl":"10.1007/s00339-025-08552-5","url":null,"abstract":"<div><p>B-site vacancy is introduced by component design to provide an easy way to detect samarium substitution defects in Sm-doped 0.68PMN-0.32PT ceramics (The optimum d₃₃ = 1004 pC/N for x = 0.025). The thorough examination of defects through positron annihilation lifetime and coincidence Doppler broadening spectroscopy indicates that with increasing Sm doping, defects as well as <span>(V_B^{''''})</span> related defects increase, while <span>(V_A^{''})</span> and <span>($$V_o^{ bullet bullet }$$)</span> decrease. The correlation analysis between the variation of defects and the results of dielectric, piezoelectric and ferroelectric tests offers powerful and conclusive proof that defects contribute to the local structural heterogeneity as well as the variation of T_C. The variation of ferroelectric, dielectric and piezoelectric parameters with Sm-doping content is ascribed to the superposition effect of the contribution from <span>(Sm_{Pb}^ cdot)</span> defects and the contribution from <span>($$V_A^{''},V_B^{''''},V_o^{ bullet bullet }$$)</span>.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}