Pub Date : 2020-08-01DOI: 10.1051/epjap/2020200165
S. Patel, Manish Kumar
In the present work, the electrocaloric (EC) effect in lead-free Sr and Sn doped (Ba0.85 Ca0.075 Sr0.075 )(Zr0.1 Ti0.88 Sn0.02 )O3 ceramic prepared by solid-state method has been investigated. The phase purity and pure perovskite phase formation with Sr and Sn doping is confirmed by X-ray diffraction. The adiabatic temperature change ΔT (due to the EC effect), entropy change (ΔS) and refrigeration capacity (RC) are estimated under various electric fields. The maximum peak values of ΔT, ΔS and RC are found as 1.5 K, 1.8 J/kg.K and 2.75 J/kg, respectively under the applied electric field of 33 kV/cm at 305 K. It is also observed that the ΔT, ΔS and RC decreases with an increase in applied temperature. Moreover, the estimated values of EC properties are significantly high which indicates that fabrication of Sr and Sn doped lead-free ceramics can be advantageous for EC applications.
{"title":"Electrocaloric properties of Sr and Sn doped BCZT lead-free ceramics","authors":"S. Patel, Manish Kumar","doi":"10.1051/epjap/2020200165","DOIUrl":"https://doi.org/10.1051/epjap/2020200165","url":null,"abstract":"In the present work, the electrocaloric (EC) effect in lead-free Sr and Sn doped (Ba0.85 Ca0.075 Sr0.075 )(Zr0.1 Ti0.88 Sn0.02 )O3 ceramic prepared by solid-state method has been investigated. The phase purity and pure perovskite phase formation with Sr and Sn doping is confirmed by X-ray diffraction. The adiabatic temperature change ΔT (due to the EC effect), entropy change (ΔS) and refrigeration capacity (RC) are estimated under various electric fields. The maximum peak values of ΔT, ΔS and RC are found as 1.5 K, 1.8 J/kg.K and 2.75 J/kg, respectively under the applied electric field of 33 kV/cm at 305 K. It is also observed that the ΔT, ΔS and RC decreases with an increase in applied temperature. Moreover, the estimated values of EC properties are significantly high which indicates that fabrication of Sr and Sn doped lead-free ceramics can be advantageous for EC applications.","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74609896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-01DOI: 10.1051/epjap/2020190323
A. Bute, Neelima Khare, Sanjiv Kumar, D. Bhattacharya, Kulwant Singh, A. Sahu, N. Chand, S. Sinha
This study narrates the findings regarding investigation of tribological properties of Bx C:Hy thin films deposited by Radio Frequency Plasma Enhanced Chemical Vapour Deposition (RF-PECVD) technique. To study tribological properties, two sets of films were prepared with variation in composition and thickness by tuning deposition parameters. Tribological properties were studied in ambience for three different applied vertical load values (5, 10 and 15 N). Lower self-bias (−75 V) seems advantageous for synthesis of Bx C:Hy films offering superior hardness, lubricity and wear resistance in tribologically stressed conditions. For a given composition, the film with the highest thickness (∼3 μm) exhibited better friction and wear resistance, offering lowest co-efficient of friction (COF) ∼0.23 for 5 N load and specific wear rate of 2.56 × 10−5 mm3 /Nm for 10 N load. Lower self-bias during deposition (−75 V) seems advantageous for synthesis of Bx C:Hy films having high hardness (∼2800 HK) and excellent Co-efficient of friction (COF).
{"title":"Tribological properties of hydrogenated boron carbide (BxC:Hy) thin films on stainless steel deposited by RF-PECVD technique","authors":"A. Bute, Neelima Khare, Sanjiv Kumar, D. Bhattacharya, Kulwant Singh, A. Sahu, N. Chand, S. Sinha","doi":"10.1051/epjap/2020190323","DOIUrl":"https://doi.org/10.1051/epjap/2020190323","url":null,"abstract":"This study narrates the findings regarding investigation of tribological properties of Bx C:Hy thin films deposited by Radio Frequency Plasma Enhanced Chemical Vapour Deposition (RF-PECVD) technique. To study tribological properties, two sets of films were prepared with variation in composition and thickness by tuning deposition parameters. Tribological properties were studied in ambience for three different applied vertical load values (5, 10 and 15 N). Lower self-bias (−75 V) seems advantageous for synthesis of Bx C:Hy films offering superior hardness, lubricity and wear resistance in tribologically stressed conditions. For a given composition, the film with the highest thickness (∼3 μm) exhibited better friction and wear resistance, offering lowest co-efficient of friction (COF) ∼0.23 for 5 N load and specific wear rate of 2.56 × 10−5 mm3 /Nm for 10 N load. Lower self-bias during deposition (−75 V) seems advantageous for synthesis of Bx C:Hy films having high hardness (∼2800 HK) and excellent Co-efficient of friction (COF).","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81966123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-01DOI: 10.1051/epjap/2020200087
Xin He, Jinliang Jie, Junbo Yang, Yunxin Han, Sen Zhang
A dual narrowband absorber operating at mid-infrared (mid-IR) frequencies was numerically investigated. The structure consists of a fine-structured silicon grating on a gold film. Each unit cell of the fine-structured silicon grating is composed of two different silicon bars. When illuminated by a transverse-magnetic (TM) polarized plane wave, the absorber will create two absorption bands. At normal incidence, the two absorption bands have respective peak wavelengths of ∼3.864 µm and ∼3.994 µm, and respective bandwidths of ∼28 nm and ∼36 nm. The level of absorption can be higher than 0.998. It is shown that the two absorption bands are related to different silicon bars in each unit cell. Moreover, the physical origin of the two absorption bands is attributed to the different surface-plasmon-polariton (SPP) modes excited in the absorber.
{"title":"Using fine-structured gratings to implement mid-infrared dual-band absorbers","authors":"Xin He, Jinliang Jie, Junbo Yang, Yunxin Han, Sen Zhang","doi":"10.1051/epjap/2020200087","DOIUrl":"https://doi.org/10.1051/epjap/2020200087","url":null,"abstract":"A dual narrowband absorber operating at mid-infrared (mid-IR) frequencies was numerically investigated. The structure consists of a fine-structured silicon grating on a gold film. Each unit cell of the fine-structured silicon grating is composed of two different silicon bars. When illuminated by a transverse-magnetic (TM) polarized plane wave, the absorber will create two absorption bands. At normal incidence, the two absorption bands have respective peak wavelengths of ∼3.864 µm and ∼3.994 µm, and respective bandwidths of ∼28 nm and ∼36 nm. The level of absorption can be higher than 0.998. It is shown that the two absorption bands are related to different silicon bars in each unit cell. Moreover, the physical origin of the two absorption bands is attributed to the different surface-plasmon-polariton (SPP) modes excited in the absorber.","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76914993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-01DOI: 10.1051/epjap/2020190302
Md. Seraj Uddin, C. Vijayan, J. Rath
We report on the synthesis of Si1−x Ge x alloy nanocrystals by very-high-frequency plasma-enhanced chemical vapor deposition (VHF PECVD) technique at different silane to germane gas flow ratio (R) in a mixture of (H2 +Ar) dilution gas and H2 dilution gas alone. TEM, SAED, EDS studies and HAADF-STEM mapping of the samples were done to investigate the NCs' size, crystallinity and distribution of Si and Ge in the Si1−x Ge x alloy NCs. The average estimated size of the NCs in all the samples are in the order of exciton Bohr radius of Ge (24.3 nm), thereby indicating the probability of good quantum confinement. The alloy nature of NCs was confirmed in Raman study. The content of Ge in SiGe NCs was evaluated from Raman spectra which show a direct correlation with the fraction of hydrogen flow in the dilution gas mixture.
本文报道了在不同硅烷/锗气体流量比(R)下，在(H2 +Ar)稀释气体和单独的H2稀释气体中，采用甚高频等离子体增强化学气相沉积(VHF PECVD)技术合成Si1−x Ge x合金纳米晶体。通过对样品的TEM、SAED、EDS和HAADF-STEM图谱分析，研究了Si1−x Ge x合金NCs中Si和Ge的尺寸、结晶度和分布。所有样品中NCs的平均估计尺寸都在激子玻尔半径为Ge (24.3 nm)的数量级，从而表明了良好量子约束的可能性。拉曼实验证实了纳米碳化物的合金性质。用拉曼光谱测定了锗纳米碳化物中Ge的含量，结果表明，锗纳米碳化物中Ge的含量与稀释气体中氢气流动的比例直接相关。
{"title":"Sensitivity of germanium content on growth conditions of silicon-germanium nanoparticles prepared in nonthermal capacitively-coupled plasmas","authors":"Md. Seraj Uddin, C. Vijayan, J. Rath","doi":"10.1051/epjap/2020190302","DOIUrl":"https://doi.org/10.1051/epjap/2020190302","url":null,"abstract":"We report on the synthesis of Si1−x Ge x alloy nanocrystals by very-high-frequency plasma-enhanced chemical vapor deposition (VHF PECVD) technique at different silane to germane gas flow ratio (R) in a mixture of (H2 +Ar) dilution gas and H2 dilution gas alone. TEM, SAED, EDS studies and HAADF-STEM mapping of the samples were done to investigate the NCs' size, crystallinity and distribution of Si and Ge in the Si1−x Ge x alloy NCs. The average estimated size of the NCs in all the samples are in the order of exciton Bohr radius of Ge (24.3 nm), thereby indicating the probability of good quantum confinement. The alloy nature of NCs was confirmed in Raman study. The content of Ge in SiGe NCs was evaluated from Raman spectra which show a direct correlation with the fraction of hydrogen flow in the dilution gas mixture.","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83716905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-01DOI: 10.1051/epjap/2020200109
M. Khalis, R. Masrour
This paper presents a new neural network-based approach that aims to use the back propagation multilayer perceptual (MLP) propagation algorithm to improve the extraction of parameters from a solar cell based on the single-diode model from the experimentally measured characteristic I (V ). The I (V ) current function as a model function for the neural network, is used the Lambert function W and I can be expressed as an explicit function. The main five parameters of interest of the function I (V ) are the photocurrent, I ph , the saturation current in inverse diode, I 0 , the ideality factor of the diode, n , the resistance in series, RS and shunt resistance, R Sh . We have used the Matlab to find the five parameters of the cell. To verify the proposed approach, we chose two different solar cells made of mono- and polycrystalline silicon. The comparison between the measured values and the results of the proposed model shows great precision. Finally, the values found of the five parameters by our approach are compared with those found by the method of least squares (MLS).
{"title":"Application of artificial neuronal networks in extracting parameters of solar cells","authors":"M. Khalis, R. Masrour","doi":"10.1051/epjap/2020200109","DOIUrl":"https://doi.org/10.1051/epjap/2020200109","url":null,"abstract":"This paper presents a new neural network-based approach that aims to use the back propagation multilayer perceptual (MLP) propagation algorithm to improve the extraction of parameters from a solar cell based on the single-diode model from the experimentally measured characteristic I (V ). The I (V ) current function as a model function for the neural network, is used the Lambert function W and I can be expressed as an explicit function. The main five parameters of interest of the function I (V ) are the photocurrent, I ph , the saturation current in inverse diode, I 0 , the ideality factor of the diode, n , the resistance in series, RS and shunt resistance, R Sh . We have used the Matlab to find the five parameters of the cell. To verify the proposed approach, we chose two different solar cells made of mono- and polycrystalline silicon. The comparison between the measured values and the results of the proposed model shows great precision. Finally, the values found of the five parameters by our approach are compared with those found by the method of least squares (MLS).","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87084273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-01DOI: 10.1051/epjap/2020200056
S. Saha, S. Mandal
We report here the effect of metal (Zn and Mn) dilution on the spin transition of Fe(phen)2 (NCS)2 thin film spin-crossover (SCO) complex. The SCO complexes are deposited on glass and indium-tin-oxide (ITO) coated glass by dip-coating technique. The growth of the films is clearly confirmed by the appearance of the sharp optical absorption band at 521–540 nm corresponding to 1 A1g to 1 T1g ligand field absorption of the SCO complex. Although the microstructure of the films remains unaffected by metal dilution, substitution of Fe(II) by either Zn(II) (diamagnetic) or Mn(II) (paramagnetic) results in subtle changes in the bonding environment of the host metal as inferred form X-ray diffraction and Raman studies. The high spin to low spin (or vice versa) transition can be triggered either by electric field or magnetic field as revealed in the measured current (I )–voltage (V ) profile or magnetization data of the films. The data further shows the effect of metal dilution on the spin transition temperatures(T1/2 ), produced hysteresis loop width and loop area, which are the crucial parameter for fabricating spin-based room temperature switching devices.
{"title":"Spin transition properties of metal (Zn, Mn) diluted Fe(phen)2(NCS)2 spin-crossover thin films","authors":"S. Saha, S. Mandal","doi":"10.1051/epjap/2020200056","DOIUrl":"https://doi.org/10.1051/epjap/2020200056","url":null,"abstract":"We report here the effect of metal (Zn and Mn) dilution on the spin transition of Fe(phen)2 (NCS)2 thin film spin-crossover (SCO) complex. The SCO complexes are deposited on glass and indium-tin-oxide (ITO) coated glass by dip-coating technique. The growth of the films is clearly confirmed by the appearance of the sharp optical absorption band at 521–540 nm corresponding to 1 A1g to 1 T1g ligand field absorption of the SCO complex. Although the microstructure of the films remains unaffected by metal dilution, substitution of Fe(II) by either Zn(II) (diamagnetic) or Mn(II) (paramagnetic) results in subtle changes in the bonding environment of the host metal as inferred form X-ray diffraction and Raman studies. The high spin to low spin (or vice versa) transition can be triggered either by electric field or magnetic field as revealed in the measured current (I )–voltage (V ) profile or magnetization data of the films. The data further shows the effect of metal dilution on the spin transition temperatures(T1/2 ), produced hysteresis loop width and loop area, which are the crucial parameter for fabricating spin-based room temperature switching devices.","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86317091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.1051/epjap/2020190014
Chuliang Zhou, Y. Bai, Zhongpeng Li, Yingying Ding, Haiyi Sun, Ye Tian
The influence of the preplasma on laser induced shockwave in the laser and aluminum-coated planar dielectric target interaction at vacuum has been investigated with the shadowgraphy method. While the laser irradiate on the aluminum-coated dielectric target at intensity of about 1017 W/cm2 , the metallic layers absorb laser energy, evaporate and ionize into plasma, it is verified that the scale length of laser-produced plasma is dramatically dependent on the contrast ratio of femtosecond-laser while the main laser pulse energy is almost kept. The characteristics of laser induced shock wave in nanosecond time scale were studied. In the nanosecond time scale, shock wave is only observed in the case of relatively short plasma scale length. This result can be explained by the dissipation of the shock wave during its propagation in the preplasma. In addition, we performed numerical simulation with MULTI2D to get an insight into the propagation of shock wave in the overdense plasma [R. Ramis, J. Meyer-ter-Vehn, and J. Ramirez, Comput. Phys. Commun. 180 , 977 (2009)].
采用影影法研究了真空条件下激光与镀铝平面介质靶相互作用中预等离子体对激光诱导冲击波的影响。当激光以约1017 W/cm2的强度照射在镀铝介质靶上时，金属层吸收激光能量，蒸发并电离成等离子体，验证了激光产生的等离子体的尺度长度与飞秒激光的对比度有很大的关系，而主激光脉冲能量基本保持不变。研究了激光诱导激波在纳秒时间尺度上的特性。在纳秒时间尺度下，只有在相对较短的等离子体尺度长度下才能观察到激波。这一结果可以用激波在预等离子体中传播过程中的耗散来解释。此外，我们利用MULTI2D进行了数值模拟，以深入了解激波在过密等离子体中的传播[R]。Ramis, J. Meyer-ter-Vehn和J. Ramirez，《计算机》。理论物理。普通。180,977(2009)]。
{"title":"Study of femtosecond laser pulse induced shockwave in aluminum-coated dielectric target","authors":"Chuliang Zhou, Y. Bai, Zhongpeng Li, Yingying Ding, Haiyi Sun, Ye Tian","doi":"10.1051/epjap/2020190014","DOIUrl":"https://doi.org/10.1051/epjap/2020190014","url":null,"abstract":"The influence of the preplasma on laser induced shockwave in the laser and aluminum-coated planar dielectric target interaction at vacuum has been investigated with the shadowgraphy method. While the laser irradiate on the aluminum-coated dielectric target at intensity of about 1017 W/cm2 , the metallic layers absorb laser energy, evaporate and ionize into plasma, it is verified that the scale length of laser-produced plasma is dramatically dependent on the contrast ratio of femtosecond-laser while the main laser pulse energy is almost kept. The characteristics of laser induced shock wave in nanosecond time scale were studied. In the nanosecond time scale, shock wave is only observed in the case of relatively short plasma scale length. This result can be explained by the dissipation of the shock wave during its propagation in the preplasma. In addition, we performed numerical simulation with MULTI2D to get an insight into the propagation of shock wave in the overdense plasma [R. Ramis, J. Meyer-ter-Vehn, and J. Ramirez, Comput. Phys. Commun. 180 , 977 (2009)].","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82267578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.1051/epjap/2020200042
Zhi Yang, Guoqiang Zheng, Peng Zhu, Cong Xu, Qiu Zhang, Ke Wang, R. Shen
Parallel bridge foils (PBF) with four strip foils, which is derived from traditional single bridge foil (SBF), was designed to study the effect of convergence and collision of plasmas and shock waves on driving flyer. Firstly, Electro-thermal simulation of PBF was performed to analyze temperature distribution before melting, which predicted the synchronous burst characteristic of PBF. Subsequently, a capacitor discharging circuit was designed to initiate bridge foils, results indicated PBF reached higher burst power in shorter time compared with SBF due to better matching between PBF and the test circuit. The flow fields of electrical explosion of bridge foils were photographed by ultra-high-speed camera, which displayed PBF almost burst simultaneously. Moreover, PBF had wider and brighter flow field visualization than SBF owing to convergence and superposition of plasma beams. Most importantly, flyer-accelerators inserted with bridge foils were prepared by MEMS technology, and comparative analysis from PDV revealed MEMS flyer-accelerator inserted with PBF had access to better velocity performances, compared with that inserted with SBF. For instance, PBF flyer-accelerator spent mere 168 ns to 2325 m/s at 900 V/0.22 µF, but SBF flyer-accelerator took 335 ns to 1073 m/s. Finally, we proposed a mathematical model for explaining the enhancement effect of flyer velocity, which to some extent showed good agreement with experimentation.
{"title":"Design, fabrication and characterization of an electrical-explosively actuated MEMS flyer-accelerator inserted with parallel bridge foils","authors":"Zhi Yang, Guoqiang Zheng, Peng Zhu, Cong Xu, Qiu Zhang, Ke Wang, R. Shen","doi":"10.1051/epjap/2020200042","DOIUrl":"https://doi.org/10.1051/epjap/2020200042","url":null,"abstract":"Parallel bridge foils (PBF) with four strip foils, which is derived from traditional single bridge foil (SBF), was designed to study the effect of convergence and collision of plasmas and shock waves on driving flyer. Firstly, Electro-thermal simulation of PBF was performed to analyze temperature distribution before melting, which predicted the synchronous burst characteristic of PBF. Subsequently, a capacitor discharging circuit was designed to initiate bridge foils, results indicated PBF reached higher burst power in shorter time compared with SBF due to better matching between PBF and the test circuit. The flow fields of electrical explosion of bridge foils were photographed by ultra-high-speed camera, which displayed PBF almost burst simultaneously. Moreover, PBF had wider and brighter flow field visualization than SBF owing to convergence and superposition of plasma beams. Most importantly, flyer-accelerators inserted with bridge foils were prepared by MEMS technology, and comparative analysis from PDV revealed MEMS flyer-accelerator inserted with PBF had access to better velocity performances, compared with that inserted with SBF. For instance, PBF flyer-accelerator spent mere 168 ns to 2325 m/s at 900 V/0.22 µF, but SBF flyer-accelerator took 335 ns to 1073 m/s. Finally, we proposed a mathematical model for explaining the enhancement effect of flyer velocity, which to some extent showed good agreement with experimentation.","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74121133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.1051/epjap/2020190213
Patrick Dietz, F. Becker, K. Keil, K. Holste, P. Klar
Neutralization of the extracted ion beam is a mandatory task for any ion thruster based space mission. The required lifetimes are in the order of ten thousand hours. This requirement is fulfilled by hollow cathodes operating with xenon, but has not been demonstrated for operation with iodine yet. Furthermore, the power consumption as well as the demand on mass flow should be kept as low as possible. Since the halogen iodine seems to be a viable alternative to xenon for operating ion thrusters, a suitable neutralizer concept that can operate with the corrosive gas for the time periods stated above is required. We propose to use a neutralizer based on an inductively coupled rf discharge as alternative to hollow cathodes. We studied the performance of a prototypical neutralizer operating with iodine as well as the inert gases xenon and krypton and compared the experimental studies with the results of global modeling.
{"title":"Performance of a rf neutralizer operating with noble gases and iodine","authors":"Patrick Dietz, F. Becker, K. Keil, K. Holste, P. Klar","doi":"10.1051/epjap/2020190213","DOIUrl":"https://doi.org/10.1051/epjap/2020190213","url":null,"abstract":"Neutralization of the extracted ion beam is a mandatory task for any ion thruster based space mission. The required lifetimes are in the order of ten thousand hours. This requirement is fulfilled by hollow cathodes operating with xenon, but has not been demonstrated for operation with iodine yet. Furthermore, the power consumption as well as the demand on mass flow should be kept as low as possible. Since the halogen iodine seems to be a viable alternative to xenon for operating ion thrusters, a suitable neutralizer concept that can operate with the corrosive gas for the time periods stated above is required. We propose to use a neutralizer based on an inductively coupled rf discharge as alternative to hollow cathodes. We studied the performance of a prototypical neutralizer operating with iodine as well as the inert gases xenon and krypton and compared the experimental studies with the results of global modeling.","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73867009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.1051/epjap/2020200037
Zhengming Zhang
The cobalt-carbon co-doped NaZn13 -type compound LaFe10.95 Co0.65 Si1.4 C0.15 (LFCSC) is one of the most promising candidates for room-temperature working substance in magnetic refrigerator due to its many excellent properties such as large reversible entropy, low cost, and short annealing time. However, owing to the narrow temperature regions of magnetic phase transition in LFCSC, the operation-temperature window for magnetic refrigeration is limited, which restricts its actual application to some extends. In this paper, it is shown that the application of high-pressure to LFCSC during annealing can tailor atomic environment and magnetic transition, which leads to a strongly expanded phase transition temperature range in LFCSC. This broadening behavior can be well understood by importing the magnetoelastic interaction of localized magnetic moments into a microscopic model. The refrigeration performance of the high-pressure annealed sample with wide phase transition temperature range is enhanced according to the relative cooling power (RCP). On the contrary, temperature averaged entropy change (TEC) exhibits a weakened value in the high-pressure annealed sample, which suggests that the magnetic cooling performance could not be effectively improved by simply expanding the phase transition temperature range in the second-order phase transition materials. However, high-pressure annealing would be helpful to the magnetic refrigeration performance for the first-order phase transition materials.
{"title":"Mechanism of broadened phase transition temperature range in LaFeCoSiC compounds prepared upon high-pressure annealing","authors":"Zhengming Zhang","doi":"10.1051/epjap/2020200037","DOIUrl":"https://doi.org/10.1051/epjap/2020200037","url":null,"abstract":"The cobalt-carbon co-doped NaZn13 -type compound LaFe10.95 Co0.65 Si1.4 C0.15 (LFCSC) is one of the most promising candidates for room-temperature working substance in magnetic refrigerator due to its many excellent properties such as large reversible entropy, low cost, and short annealing time. However, owing to the narrow temperature regions of magnetic phase transition in LFCSC, the operation-temperature window for magnetic refrigeration is limited, which restricts its actual application to some extends. In this paper, it is shown that the application of high-pressure to LFCSC during annealing can tailor atomic environment and magnetic transition, which leads to a strongly expanded phase transition temperature range in LFCSC. This broadening behavior can be well understood by importing the magnetoelastic interaction of localized magnetic moments into a microscopic model. The refrigeration performance of the high-pressure annealed sample with wide phase transition temperature range is enhanced according to the relative cooling power (RCP). On the contrary, temperature averaged entropy change (TEC) exhibits a weakened value in the high-pressure annealed sample, which suggests that the magnetic cooling performance could not be effectively improved by simply expanding the phase transition temperature range in the second-order phase transition materials. However, high-pressure annealing would be helpful to the magnetic refrigeration performance for the first-order phase transition materials.","PeriodicalId":12228,"journal":{"name":"European Physical Journal-applied Physics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80176426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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