An analysis of an annular electron beam propagating along a cylindrical grating with external magnetic field Bo is presented. The grating comprises a dielectric in its slots. The dispersion relation of the modes is derived. The results demonstrate that the dielectric shifts the frequencies of the system modes to smaller values. The growth rates of the modes which are in phase with the beam are also considered. It is found that the decline in the growth rate is brought about by the dielectric. In addition, increasing the thickness of the dielectric and decreasing the height of the slots cause it to rise. The effect of beam thickness on growth rate is considered too. This is shown to increase and then fall as beam thickness increases. These results show that utilizing cylindrical grating loaded with dielectric has a promising effect on developing new kinds of compact high-efficient THz free-electron lasers based on Smith–Purcell radiation. Edited by: A. B. Márquez
{"title":"Theory of terahertz Smith-Purcell radiation from a cylindrical grating","authors":"Z. Rezaei, B. Farokhi","doi":"10.4279/pip.110007","DOIUrl":"https://doi.org/10.4279/pip.110007","url":null,"abstract":"An analysis of an annular electron beam propagating along a cylindrical grating with external magnetic field Bo is presented. The grating comprises a dielectric in its slots. The dispersion relation of the modes is derived. The results demonstrate that the dielectric shifts the frequencies of the system modes to smaller values. The growth rates of the modes which are in phase with the beam are also considered. It is found that the decline in the growth rate is brought about by the dielectric. In addition, increasing the thickness of the dielectric and decreasing the height of the slots cause it to rise. The effect of beam thickness on growth rate is considered too. This is shown to increase and then fall as beam thickness increases. These results show that utilizing cylindrical grating loaded with dielectric has a promising effect on developing new kinds of compact high-efficient THz free-electron lasers based on Smith–Purcell radiation. \u0000Edited by: A. B. Márquez","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48360778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Francisco-López, B. Han, D. Lagarde, X. Marie, B. Urbaszek, C. Robert, A. Goñi
We have studied the optical properties of $WSe_2$ monolayers (ML) by means of photoluminescence (PL), PL excitation (PLE) and Raman scattering spectroscopy at room temperature and as a function of hydrostatic pressure up to ca. 12 GPa. For comparison the study comprises two cases: A single $WSe_2$ ML directly transferred onto one of the diamonds of the diamond anvil cell and a $WSe_2$ ML encapsulated into hexagonal boron nitride (hBN) layers. The pressure dependence of the A and B exciton, as determined by PL and PLE, respectively, is very different for the case of the bare $WSe_2$ ML and the $hBN/WSe_2-ML/hBN$ heterostructure. Whereas for the latter the A and B exciton energy increases linearly with increasing pressure at a rate of 3.5 to 3.8 meV/GPa, for the bare $WSe_2$ ML the A and B exciton energy decreases with a coefficient of -3.1 and -1.3 meV/GPa, respectively. We interpret that this behavior is due to a different stress situation. For a single ML the stress tensor is essentially uniaxial with the compressive stress component in the direction perpendicular to the plane of the ML. In contrast, for the substantially thicker $hBN/WSe_2-ML/hBN$ heterostructure the compression is hydrostatic. The results from an analysis of the pressure dependence of the frequency of Raman active modes comply with the interpretation of having a different stress situation in each case. Reviewed by: A. San Miguel, Institut Lumière Matière, Université de Lyon, France; Edited by: J. S. Reparaz
利用光致发光(PL)、PL激发(PLE)和拉曼散射光谱，研究了WSe_2单层膜(ML)在室温下的光学性质和高达12 GPa的静水压力的函数关系。为了进行比较，本研究分为两种情况:一种是将单个$WSe_2$ ML直接转移到金刚石砧细胞中的一个金刚石上，另一种是将$WSe_2$ ML包裹在六方氮化硼(hBN)层中。在裸WSe_2-ML和hBN/WSe_2-ML/hBN异质结构中，分别用PL和PLE测定的A和B激子的压力依赖性是非常不同的。而对于后者，A和B激子能量随压力的增加而线性增加，速率为3.5 ~ 3.8 meV/GPa，而对于裸WSe_2 - ML, A和B激子能量分别以-3.1和-1.3 meV/GPa的系数下降。我们解释说，这种行为是由于不同的压力情况。对于单个ML，应力张量基本上是单轴的，压应力分量垂直于ML平面的方向。相反，对于较厚的$hBN/WSe_2-ML/hBN$异质结构，压缩是流体静力的。对拉曼主动模频率的压力依赖性分析结果符合每种情况下具有不同应力情况的解释。评审:A. San Miguel，法国里昂大学Institut lumi mati研究所;编辑:J. S. Reparaz
{"title":"On the impact of the stress situation on the optical properties of $WSe_2$ monolayers under high pressure","authors":"A. Francisco-López, B. Han, D. Lagarde, X. Marie, B. Urbaszek, C. Robert, A. Goñi","doi":"10.4279/PIP.110005","DOIUrl":"https://doi.org/10.4279/PIP.110005","url":null,"abstract":"We have studied the optical properties of $WSe_2$ monolayers (ML) by means of photoluminescence (PL), PL excitation (PLE) and Raman scattering spectroscopy at room temperature and as a function of hydrostatic pressure up to ca. 12 GPa. For comparison the study comprises two cases: A single $WSe_2$ ML directly transferred onto one of the diamonds of the diamond anvil cell and a $WSe_2$ ML encapsulated into hexagonal boron nitride (hBN) layers. The pressure dependence of the A and B exciton, as determined by PL and PLE, respectively, is very different for the case of the bare $WSe_2$ ML and the $hBN/WSe_2-ML/hBN$ heterostructure. Whereas for the latter the A and B exciton energy increases linearly with increasing pressure at a rate of 3.5 to 3.8 meV/GPa, for the bare $WSe_2$ ML the A and B exciton energy decreases with a coefficient of -3.1 and -1.3 meV/GPa, respectively. We interpret that this behavior is due to a different stress situation. For a single ML the stress tensor is essentially uniaxial with the compressive stress component in the direction perpendicular to the plane of the ML. In contrast, for the substantially thicker $hBN/WSe_2-ML/hBN$ heterostructure the compression is hydrostatic. The results from an analysis of the pressure dependence of the frequency of Raman active modes comply with the interpretation of having a different stress situation in each case. \u0000Reviewed by: A. San Miguel, Institut Lumière Matière, Université de Lyon, France; Edited by: J. S. Reparaz","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44340001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Jara, J. A. Barreda-Argüeso, Jesús González, R. Valiente, F. Rodríguez
We have investigated the crystal structure of $Cs_2CuCl_4$ in the 0-20 GPa range as a function of pressure and how pressure affects its electronic properties by means of optical absorption spectroscopy. In particular, we focused on the electronic properties in the low-pressure Pnma phase, which are mainly related to the tetrahedral $CuCl_4^{2-}$ units distorted by the Jahn-Teller effect. This study provides a complete characterization of the electronic structure of $Cs_2CuCl_4$ in the Pmna phase as a function of the cell volume and the $Cu-Cl$ bond length, $R_{Cu-Cl}$. Interestingly, the opposite shift of the charge-transfer band-gap and the $Cu^{2+}$ d-d crystal-field band shift with pressure are responsible for the strong piezochromism of $Cs_2CuCl_4$. We have also explored the high-pressure structure of $Cs_2CuCl_4$ above 4.9 GPa yielding structural transformations that are probably associated with a change of coordination around $Cu^{2+}$. Since the high-pressure phase appears largely amorphized, any structural information from X-ray diffraction is ruled out. We use electronic probes to get structural information of the high-pressure phase. Edited by: A. Goñi, A. Cantarero, J. S. Reparaz
用光学吸收光谱法研究了$Cs_2CuCl_4$在0-20 GPa范围内的晶体结构与压力的关系，以及压力对其电子性能的影响。我们特别关注了低压Pnma相的电子性质，这主要与四面体$CuCl_4^{2-}$单位被Jahn-Teller效应扭曲有关。本研究完整地描述了$Cs_2CuCl_4$在Pmna相中的电子结构与细胞体积和$Cu-Cl$键长$R_{Cu-Cl}$的关系。有趣的是，电荷转移带隙的反向位移和Cu^{2+}$ d-d晶体场带场随压力的位移是导致$Cs_2CuCl_4$强压变色的原因。我们还研究了$Cs_2CuCl_4$在4.9 GPa以上的高压结构，产生了可能与$Cu^{2+}$周围配位变化有关的结构转变。由于高压相大部分非晶化，x射线衍射的任何结构信息都被排除在外。我们使用电子探针来获取高压相的结构信息。编辑:A. Goñi, A. Cantarero, J. S. Reparaz
{"title":"Structural correlations in $Cs_2CuCl_4$: Pressure dependence of electronic structures","authors":"E. Jara, J. A. Barreda-Argüeso, Jesús González, R. Valiente, F. Rodríguez","doi":"10.4279/PIP.110004","DOIUrl":"https://doi.org/10.4279/PIP.110004","url":null,"abstract":"We have investigated the crystal structure of $Cs_2CuCl_4$ in the 0-20 GPa range as a function of pressure and how pressure affects its electronic properties by means of optical absorption spectroscopy. In particular, we focused on the electronic properties in the low-pressure Pnma phase, which are mainly related to the tetrahedral $CuCl_4^{2-}$ units distorted by the Jahn-Teller effect. This study provides a complete characterization of the electronic structure of $Cs_2CuCl_4$ in the Pmna phase as a function of the cell volume and the $Cu-Cl$ bond length, $R_{Cu-Cl}$. Interestingly, the opposite shift of the charge-transfer band-gap and the $Cu^{2+}$ d-d crystal-field band shift with pressure are responsible for the strong piezochromism of $Cs_2CuCl_4$. We have also explored the high-pressure structure of $Cs_2CuCl_4$ above 4.9 GPa yielding structural transformations that are probably associated with a change of coordination around $Cu^{2+}$. Since the high-pressure phase appears largely amorphized, any structural information from X-ray diffraction is ruled out. We use electronic probes to get structural information of the high-pressure phase. \u0000Edited by: A. Goñi, A. Cantarero, J. S. Reparaz","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45089747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Kuwayama, K. Matsuura, Y. Mizukami, S. Kasahara, Y. Matsuda, T. Shibauchi, Y. Uwatoko, N. Fujiwara
Recently, FeSe$_{1-x}$S$_x$ systems have received much attention because of the unique pressure-temperature phase diagram. We performed $^{77}$Se-NMR measurements on a single crystal of FeSe$_{0.88}$S$_{0.12}$ to investigate its microscopic properties. The shift of $^{77}$Se spectra exhibits anomalous enhancement at $1.0~mathrm{GPa}$, suggesting a topological change in the Fermi surfaces, so-called Lifshitz transition, occurs at $1.0~mathrm{GPa}$. The magnetic fluctuation simultaneously changes its properties, which implies a change in the dominant nesting vector. Edited by: A. Goñi, A. Cantarero, J. S. Reparaz
{"title":"Pressure-induced Lifshitz transition in FeSe$_{0.88}$S$_{0.12}$ probed via $^{77}$Se-NMR","authors":"T. Kuwayama, K. Matsuura, Y. Mizukami, S. Kasahara, Y. Matsuda, T. Shibauchi, Y. Uwatoko, N. Fujiwara","doi":"10.4279/PIP.110003","DOIUrl":"https://doi.org/10.4279/PIP.110003","url":null,"abstract":"Recently, FeSe$_{1-x}$S$_x$ systems have received much attention because of the unique pressure-temperature phase diagram. We performed $^{77}$Se-NMR measurements on a single crystal of FeSe$_{0.88}$S$_{0.12}$ to investigate its microscopic properties. The shift of $^{77}$Se spectra exhibits anomalous enhancement at $1.0~mathrm{GPa}$, suggesting a topological change in the Fermi surfaces, so-called Lifshitz transition, occurs at $1.0~mathrm{GPa}$. The magnetic fluctuation simultaneously changes its properties, which implies a change in the dominant nesting vector. \u0000Edited by: A. Goñi, A. Cantarero, J. S. Reparaz","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44262086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Fujiwara, M. Takeuchi, T. Kuwayama, Shusaku Nakagawa, S. Iimura, S. Matsuishi, H. Hosono
A prototypical electron-doped iron-based superconductor $LaFeAsO_{1-x}H_x$ undergoes an antiferromagnetic (AF) phase for $x geq 0.49$. We performed NMR measurements on $LaFeAsO_{0.4}H_{0.6}$ at 3.7 GPa to investigate the magnetic properties in the vicinity of a pressure-induced QCP. The linewidth of $~^1H$-NMR spectra broadens at low temperatures below 30 K, suggesting that the ordered spin moments remain at 3.7 GPa. The coexistence of gapped and gapless spin excitations was confirmed in the ordered state from the relaxation time $T_1$ of $~^{75}As$. The pressure-induced QCP is estimated to be 4.1 GPa from the pressure dependence of the gapped excitation.
{"title":"Nuclear magnetic resonance on $LaFeAsO_{0.4}H_{0.6}$ at 3.7 GPa","authors":"N. Fujiwara, M. Takeuchi, T. Kuwayama, Shusaku Nakagawa, S. Iimura, S. Matsuishi, H. Hosono","doi":"10.4279/PIP.110002","DOIUrl":"https://doi.org/10.4279/PIP.110002","url":null,"abstract":"A prototypical electron-doped iron-based superconductor $LaFeAsO_{1-x}H_x$ undergoes an antiferromagnetic (AF) phase for $x geq 0.49$. We performed NMR measurements on $LaFeAsO_{0.4}H_{0.6}$ at 3.7 GPa to investigate the magnetic properties in the vicinity of a pressure-induced QCP. The linewidth of $~^1H$-NMR spectra broadens at low temperatures below 30 K, suggesting that the ordered spin moments remain at 3.7 GPa. The coexistence of gapped and gapless spin excitations was confirmed in the ordered state from the relaxation time $T_1$ of $~^{75}As$. The pressure-induced QCP is estimated to be 4.1 GPa from the pressure dependence of the gapped excitation.","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48624921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Barrere, J. Brum, Alexandre L’Her, Gustavo L. Saras'ua, C. Cabeza
Improved understanding of how vortices develop and propagate under pulsatile flow can shed important light on the mixing and transport processes occurring in such systems, including the transition to turbulent regime. For example, the characterization of pulsatile flows in obstructed artery models serves to encourage research into flow-induced phenomena associated with changes in morphology, blood viscosity, wall elasticity and flow rate. In this work, an axisymmetric rigid model was used to study the behaviour of the flow pattern with varying degrees constriction ($d_0$) and mean Reynolds ($bar{Re}$) and Womersley numbers ($alpha$). Velocity fields were obtained experimentally using Digital Particle Image Velocimetry and generated numerically. For the acquisition of data, $bar{Re}$ was varied from 385 to 2044, $d_0$ was 1.0 cm and 1.6 cm, and $alpha$ was varied from 17 to 33 in the experiments and from 24 to 50 in the numerical simulations. Results for the Reynolds number considered showed that the flow pattern consisted of two main structures: a central jet around the tube axis and a recirculation zone adjacent to the inner wall of the tube, where vortices shed. Using the vorticity fields, the trajectory of vortices was tracked and their displacement over their lifetime calculated. The analysis led to a scaling law equation for maximum vortex displacement as a function of a dimensionless variable dependent on the system parameters Re and $alpha$.
{"title":"Vortex dynamics under pulsatile flow in axisymmetric constricted tubes","authors":"N. Barrere, J. Brum, Alexandre L’Her, Gustavo L. Saras'ua, C. Cabeza","doi":"10.4279/pip.120002","DOIUrl":"https://doi.org/10.4279/pip.120002","url":null,"abstract":"Improved understanding of how vortices develop and propagate under pulsatile flow can shed important light on the mixing and transport processes occurring in such systems, including the transition to turbulent regime. For example, the characterization of pulsatile flows in obstructed artery models serves to encourage research into flow-induced phenomena associated with changes in morphology, blood viscosity, wall elasticity and flow rate. In this work, an axisymmetric rigid model was used to study the behaviour of the flow pattern with varying degrees constriction ($d_0$) and mean Reynolds ($bar{Re}$) and Womersley numbers ($alpha$). Velocity fields were obtained experimentally using Digital Particle Image Velocimetry and generated numerically. For the acquisition of data, $bar{Re}$ was varied from 385 to 2044, $d_0$ was 1.0 cm and 1.6 cm, and $alpha$ was varied from 17 to 33 in the experiments and from 24 to 50 in the numerical simulations. Results for the Reynolds number considered showed that the flow pattern consisted of two main structures: a central jet around the tube axis and a recirculation zone adjacent to the inner wall of the tube, where vortices shed. Using the vorticity fields, the trajectory of vortices was tracked and their displacement over their lifetime calculated. The analysis led to a scaling law equation for maximum vortex displacement as a function of a dimensionless variable dependent on the system parameters Re and $alpha$.","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46732104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Pravica, Sarah N. Schyck, Blake Harris, P. Cifligu, Eunja Kim, B. Billinghurst
By irradiating a pressurized mixture of a fluorine-bearing compound ($XeF_2$) and $HgF_2$ with synchrotron hard x-rays (>7 keV) inside a diamond anvil cell, we have observed dramatic changes in the far-infrared spectrum within the 30-35 GPa pressure range which suggest that we may have formed $HgF_4$ in the following way: $XeF_2 xrightarrow{hv} Xe + F_2$ (photochemically) and $HgF_2 + F_2 rightarrow HgF_4$ (30 GPa < P < 35 GPa). This lends credence to recent theoretical calculations by Botana et al. that suggest that Hg may behave as a transition metal at high pressure in an environment with an excess of molecular fluorine. The spectral changes were observed to be reversible during pressure cycling above and below the above mentioned pressure range until a certain point when we suspect that molecular fluorine diffused out of the sample at lower pressure. Upon pressure release, $HgF_2$ and trace $XeF_2$ were observed to be remaining in the sample chamber suggesting that much of the $Xe$ and $F_2$ diffused and leaked out from the sample chamber. Received: 29 October 2018, Accepted: 18 January 2019; Edited by: A. Goñi, A. Cantarero, J. S. Reparaz; DOI: http://dx.doi.org/10.4279/PIP.110001 Cite as: M Pravica, S Schyck, B Harris, P Cifligu, E Kim, B Billinghurst, Papers in Physics 11, 110001 (2019). This paper, by M Pravica, S Schyck, B Harris, P Cifligu, E Kim, B Billinghurst, is licensed under the Creative Commons Attribution License 4.0.
{"title":"Fluorine chemistry at extreme conditions: possible synthesis of $HgF_4$","authors":"M. Pravica, Sarah N. Schyck, Blake Harris, P. Cifligu, Eunja Kim, B. Billinghurst","doi":"10.4279/PIP.110001","DOIUrl":"https://doi.org/10.4279/PIP.110001","url":null,"abstract":"By irradiating a pressurized mixture of a fluorine-bearing compound ($XeF_2$) and $HgF_2$ with synchrotron hard x-rays (>7 keV) inside a diamond anvil cell, we have observed dramatic changes in the far-infrared spectrum within the 30-35 GPa pressure range which suggest that we may have formed $HgF_4$ in the following way: $XeF_2 xrightarrow{hv} Xe + F_2$ (photochemically) and $HgF_2 + F_2 rightarrow HgF_4$ (30 GPa < P < 35 GPa). This lends credence to recent theoretical calculations by Botana et al. that suggest that Hg may behave as a transition metal at high pressure in an environment with an excess of molecular fluorine. The spectral changes were observed to be reversible during pressure cycling above and below the above mentioned pressure range until a certain point when we suspect that molecular fluorine diffused out of the sample at lower pressure. Upon pressure release, $HgF_2$ and trace $XeF_2$ were observed to be remaining in the sample chamber suggesting that much of the $Xe$ and $F_2$ diffused and leaked out from the sample chamber. \u0000 \u0000Received: 29 October 2018, Accepted: 18 January 2019; Edited by: A. Goñi, A. Cantarero, J. S. Reparaz; DOI: http://dx.doi.org/10.4279/PIP.110001 \u0000Cite as: M Pravica, S Schyck, B Harris, P Cifligu, E Kim, B Billinghurst, Papers in Physics 11, 110001 (2019). \u0000This paper, by M Pravica, S Schyck, B Harris, P Cifligu, E Kim, B Billinghurst, is licensed under the Creative Commons Attribution License 4.0. \u0000 ","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46485301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Ishigaki, J. Gouchi, S. Nagasaki, J. G. Cheng, Y. Uwatoko
The two-stage 6-8 multi-anvil (MA8) apparatus is an important large-volume, high-pressure technique that has been widely used in the high pressure mineralogy and material synthesis, mainly at room temperature or above. Recently, we have successfully developed a two-stage MA8 apparatus for low-temperature physical property measurements. The first-stage anvils at top and bottom sides are fabricated as a single piece in order to reduce the total size of the cylindrical module, which is put in a top-loading high pressure cryostat and compressed by a 1000 ton hydraulic press. A castable, split octahedral gasket with integrated fin was specifically designed in order to introduce the electrical leads from the inside sample container filled with a liquid pressure transmitting medium. By using tungsten carbide (WC) second-stage cubes with a truncated edge length of 3 mm and an octahedral gasket with an edge length of 6 mm, we have successfully generated pressure over 20 GPa at room temperature. Since the high pressure limit can be pushed to nearly 100 GPa by using the sintered diamond second-stage cubes, our MA8 apparatus has a great potential to expand the current pressure capacity for precise low-temperature measurements with a large sample volume. Edited by: A. Goñi, A. Cantarero, J. S. Reparaz
两段式6-8多砧(MA8)装置是一种重要的大体积高压技术，广泛应用于室温及以上高压矿物学和材料合成领域。最近，我们成功地开发了一种用于低温物性测量的两级MA8仪器。为了减小圆柱形模块的总尺寸，顶部和底部的第一级砧被制作成一个整体，圆柱形模块被放入顶部加载的高压低温恒温器中，并由1000吨液压机压缩。为了将电引线从充满液体压力传递介质的样品容器内部引入，专门设计了一种可浇注的、带集成鳍片的分裂八面体衬垫。利用截断边长为3mm的碳化钨(WC)二级立方体和边长为6mm的八面体垫片，我们成功地在室温下产生了超过20gpa的压力。由于使用烧结金刚石第二阶段立方体可以将高压极限推至近100 GPa，因此我们的MA8仪器具有很大的潜力，可以扩大当前的压力容量，用于大样本量的精确低温测量。编辑:A. Goñi, A. Cantarero, J. S. Reparaz
{"title":"Development of two-stage multi-anvil apparatus for low-temperature measurements","authors":"K. Ishigaki, J. Gouchi, S. Nagasaki, J. G. Cheng, Y. Uwatoko","doi":"10.4279/pip.110006","DOIUrl":"https://doi.org/10.4279/pip.110006","url":null,"abstract":"The two-stage 6-8 multi-anvil (MA8) apparatus is an important large-volume, high-pressure technique that has been widely used in the high pressure mineralogy and material synthesis, mainly at room temperature or above. Recently, we have successfully developed a two-stage MA8 apparatus for low-temperature physical property measurements. The first-stage anvils at top and bottom sides are fabricated as a single piece in order to reduce the total size of the cylindrical module, which is put in a top-loading high pressure cryostat and compressed by a 1000 ton hydraulic press. A castable, split octahedral gasket with integrated fin was specifically designed in order to introduce the electrical leads from the inside sample container filled with a liquid pressure transmitting medium. By using tungsten carbide (WC) second-stage cubes with a truncated edge length of 3 mm and an octahedral gasket with an edge length of 6 mm, we have successfully generated pressure over 20 GPa at room temperature. Since the high pressure limit can be pushed to nearly 100 GPa by using the sintered diamond second-stage cubes, our MA8 apparatus has a great potential to expand the current pressure capacity for precise low-temperature measurements with a large sample volume. Edited by: A. Goñi, A. Cantarero, J. S. Reparaz","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71011144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have conducted a compound pendulum experiment using Arduino and an associated two-axis accelerometer sensor as measuring device. We have shown that the use of an accelerometer to measure both radial and orbital accelerations of the pendulum at different positions along its axis offers the possibility of performing a more complex analysis compared to the usual analysis of the pendulum experiment. In this way, we have shown that this classical experiment can lead to an interesting and low-cost experiment in mechanics.
{"title":"Physical pendulum experiment re-investigated with an accelerometer sensor","authors":"C. Dauphin, F. Bouquet","doi":"10.4279/PIP.100008","DOIUrl":"https://doi.org/10.4279/PIP.100008","url":null,"abstract":"We have conducted a compound pendulum experiment using Arduino and an associated two-axis accelerometer sensor as measuring device. We have shown that the use of an accelerometer to measure both radial and orbital accelerations of the pendulum at different positions along its axis offers the possibility of performing a more complex analysis compared to the usual analysis of the pendulum experiment. In this way, we have shown that this classical experiment can lead to an interesting and low-cost experiment in mechanics.","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2018-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46192956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Hilberer, G. Laurent, A. Lorin, A. Partier, J. Bobroff, F. Bouquet, C. Even, J. Fischbach, C. Marrache-Kikuchi, M. Monteverde, B. Pilette, Q. Quay
The current performances of single-board microcontrollers render them attractive, not only for basic applications, but also for more elaborate projects, amongst which are physics teaching or research. In this article, we show how temperature-dependent transport measurements can be performed by using an Arduino board, from cryogenic temperatures up to room temperature or above. We focus on two of the main issues for this type of experiments: the determination of the sample temperature and the measurement of its resistance. We also detail two student-led experiments: evidencing the magnetocaloric effect in Gadolinium and measuring the resistive transition of a high critical temperature superconductor. Received: 7 July 2018, Accepted: 27 September 2018; Edited by: A. Marti, M. Monteiro; Reviewed by: R. Marotti, Instituto de Fisica, Facultad de Ingenieria - Universidad de la Republica, Uruguay; DOI: http://dx.doi.org/10.4279/PIP.100007 Cite as: A Hilberer, G Laurent, A Lorin, A Partier, J Bobroff, F Bouquet, C Even, J M Fischbach, C A Marrache Kikuchi, M Monteverde, B Pilette, Q Quay, Papers in Physics 10, 100007(2018) This paper, by A Hilberer, G Laurent, A Lorin, A Partier, J Bobroff, F Bouquet, C Even, J M Fischbach, C A Marrache Kikuchi, M Monteverde, B Pilette, Q Quay , is licensed under the Creative Commons Attribution License 4.0 .
单板微控制器目前的性能使其具有吸引力，不仅适用于基本应用，也适用于更复杂的项目，其中包括物理教学或研究。在这篇文章中，我们展示了如何使用Arduino板进行与温度相关的传输测量，从低温到室温或更高。我们关注这类实验的两个主要问题：样品温度的确定和电阻的测量。我们还详细介绍了两个由学生主导的实验：证明钆中的磁热效应和测量高临界温度超导体的电阻跃迁。接收日期：2018年7月7日，接收日期：2019年9月27日；编辑：A.Marti，M.Monteiro；审查人：R.Marotti，乌拉圭共和国大学Ingenieria学院财政研究所；DOI：http://dx.doi.org/10.4279/PIP.100007引用为：A Hilberer，G Laurent，A Lorin，A Partier，J Bobroff，F Bouquet，C Even，J M Fischbach，C A Marrache Kikuchi，M Monteverde，B Pilette，Q Quay，物理学论文10，100007（2018），根据知识共享署名许可4.0获得许可。
{"title":"Temperature-dependent transport measurements with Arduino","authors":"A. Hilberer, G. Laurent, A. Lorin, A. Partier, J. Bobroff, F. Bouquet, C. Even, J. Fischbach, C. Marrache-Kikuchi, M. Monteverde, B. Pilette, Q. Quay","doi":"10.4279/pip.100007","DOIUrl":"https://doi.org/10.4279/pip.100007","url":null,"abstract":"The current performances of single-board microcontrollers render them attractive, not only for basic applications, but also for more elaborate projects, amongst which are physics teaching or research. In this article, we show how temperature-dependent transport measurements can be performed by using an Arduino board, from cryogenic temperatures up to room temperature or above. We focus on two of the main issues for this type of experiments: the determination of the sample temperature and the measurement of its resistance. We also detail two student-led experiments: evidencing the magnetocaloric effect in Gadolinium and measuring the resistive transition of a high critical temperature superconductor. Received: 7 July 2018, Accepted: 27 September 2018; Edited by: A. Marti, M. Monteiro; Reviewed by: R. Marotti, Instituto de Fisica, Facultad de Ingenieria - Universidad de la Republica, Uruguay; DOI: http://dx.doi.org/10.4279/PIP.100007 Cite as: A Hilberer, G Laurent, A Lorin, A Partier, J Bobroff, F Bouquet, C Even, J M Fischbach, C A Marrache Kikuchi, M Monteverde, B Pilette, Q Quay, Papers in Physics 10, 100007(2018) This paper, by A Hilberer, G Laurent, A Lorin, A Partier, J Bobroff, F Bouquet, C Even, J M Fischbach, C A Marrache Kikuchi, M Monteverde, B Pilette, Q Quay , is licensed under the Creative Commons Attribution License 4.0 .","PeriodicalId":19791,"journal":{"name":"Papers in Physics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2018-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49439899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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