Journal of the Physical Society of Japan最新文献

{"title":"Collinear Antiferromagnet SmPt6Al3 with a Sm Honeycomb Structure Centered by Pt Triangles","authors":"Ryohei Oishi, Yasuyuki Shimura, Kazunori Umeo, Takahiro Onimaru, Takeshi Matsumura, Mitsuru Tsukagoshi, Kenshin Kurauchi, Hiroto Nitta, Toshiro Takabatake","doi":"10.7566/jpsj.93.034707","DOIUrl":"https://doi.org/10.7566/jpsj.93.034707","url":null,"abstract":"We report a single-crystal study on the magnetism of the Sm honeycomb compound SmPt₆Al₃ with the trigonal NdPt₆Al₃-type structure by the measurements of the magnetic susceptibility <i>χ</i>, electrical resistivity, specific heat, and resonant X-ray diffraction. The trivalent state of the Sm ion is indicated by the fact that the lattice parameters fall on the lanthanoid contraction lines for the <i>R</i>³⁺Pt₆Al₃ series. For <tex-math space=\"preserve\" version=\"MathJax\">(Bparallel c)</tex-math>, <i>χ</i>(<i>T</i>) shows a cusp at <i>T</i>_N = 6.5 K and strongly decreases on cooling below <i>T</i>_N, whereas <i>χ</i>(<i>T</i>) for <tex-math space=\"preserve\" version=\"MathJax\">(B perp c)</tex-math> continues to increase without showing any anomaly at <i>T</i>_N. Application of <tex-math space=\"preserve\" version=\"MathJax\">(Bparallel c)</tex-math> = 12 T depresses <i>T</i>_N to 4.6 K, whereas <i>T</i>_N remains at 6.4 K in <tex-math space=\"preserve\" version=\"MathJax\">(B perp c)</tex-math> = 14 T. The isothermal magnetization curves at 1.8 K for both <tex-math space=\"preserve\" version=\"MathJax\">(Bparallel c)</tex-math> and <tex-math space=\"preserve\" version=\"MathJax\">(B perp c)</tex-math> have no spontaneous moment. These magnetic properties of SmPt₆Al₃ indicate a collinear antiferromagnetic structure of the ordered moments pointing toward the <i>c</i> axis. This magnetic structure is verified by the Sm resonant X-ray diffraction measurement which revealed the <tex-math space=\"preserve\" version=\"MathJax\">([0,0,0])</tex-math> propagation vector. By comparing the magnetic properties of SmPt₆Al₃ with those for the canted antiferromagnet GdPt₆Al₃, we highlight the role of Dzyaloshinskii–Moriya interaction in the series of isostructural compounds with the centrosymmetric NdPt₆Al₃-type structure.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"16 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139977645","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}

{"title":"Experimental Study and Analysis of Sub-Micron Scale Air Gap Breakdown","authors":"Guoda Wang, Yanzhou Sun, Hao Zhang, Guokai Ma, Laijun Zhao","doi":"10.7566/jpsj.93.034502","DOIUrl":"https://doi.org/10.7566/jpsj.93.034502","url":null,"abstract":"In order to study the mechanism of submicron-scale air gap discharge, the gas discharge experiment with electrode gap of 0.3–10 um was carried out by using nano-positioning system under atmospheric pressure. The breakdown voltages of stainless steel, brass, copper, and aluminum electrodes were measured. The experimental results are obviously deviated from the Paschen curve, and the Paschen curve cannot explain the air gap breakdown voltage. It is found that in the range of 0.3–5 um, the material work function significantly affects the air gap breakdown voltage, and it is not obvious in the range of 5–10 um. By studying the breakdown field strength, current density and F–N theory, it is found that when the electrode gap is 0.3–5 um, the field emission is dominant, resulting in the breakdown voltage deviating from the Paschen curve. In addition, the breakdown voltages under different discharge mechanisms are numerically calculated, and the numerical results are compared with the experimental results. The results show that only field emission needs to be considered at the gap of 0.3–2 um, and other discharge mechanisms can be ignored. Through the research of this paper, it provides a basis for the in-depth study of sub-micron electrical breakdown and the design of microelectronic devices.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"20 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139977769","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}

{"title":"Weak Kondo Coupling Antiferromagnet CePd3Sn2 with Quasi-One-Dimensional Ce Chains","authors":"Yudai Kawaue, Ryohei Oishi, Chongli Yang, Rikako Yamamoto, Yasuyuki Shimura, Kazunori Umeo, Takahiro Onimaru, Devashibhai T. Adroja, Helen C. Walker, Toshiro Takabatake","doi":"10.7566/jpsj.93.034706","DOIUrl":"https://doi.org/10.7566/jpsj.93.034706","url":null,"abstract":"CePd₃Sn₂ with Ce-chains along the orthorhombic <i>b</i> axis has been reported to order antiferromagnetically at <i>T</i>_N ∼ 0.6 K. Above <i>T</i>_N, the specific heat <i>C</i>(<i>T</i>) exhibits a long tail whose origin remains elusive. Here we report on the physical properties of single-crystalline samples inferred from electrical resistivity <i>ρ</i>(<i>T</i>), magnetization <i>M</i>(<i>B</i>), and <i>C</i>(<i>T</i>). The measurements reveal rather weak anisotropic properties characterized by the lowest <i>ρ</i>(<i>T</i>) and the highest saturation <i>M</i>(<i>B</i>) along the <i>b</i> axis. The <i>ρ</i>(<i>T</i>) data along the three principal directions exhibit no clear signature of Kondo scattering and decrease with negative curvatures on cooling from 2 K to <i>T</i>_N = 0.67 K. The magnetic susceptibility and inelastic neutron scattering data are reproduced by the crystal electric field (CEF) model for the Ce³⁺ ion with two excited CEF doublets at rather low energies 27 and 191 K, respectively, above the ground state doublet. The isothermal <i>M</i>(<i>B</i>) curves at 0.3 K show metamagnetic transitions at <i>B</i> || <i>b</i> = 1.8 T and <i>B</i> || <i>c</i> = 1.5 T and upward increases before saturation for the three directions. The antiferromagnetic order is destroyed by the application of magnetic field in an anisotropic way at around <i>B</i> || <i>b</i> = 3 T, <i>B</i> || <i>c</i> = 4 T, and <i>B</i> || <i>a</i> = 5 T. The obtained results are discussed by comparing with those reported for quasi-one-dimensional Ce compounds.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"34 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139981634","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}

{"title":"Bayesian Integration for Hamiltonian Parameters of Crystal Field","authors":"Rei Nishimura, Shun Katakami, Kenji Nagata, Masaichiro Mizumaki, Masato Okada","doi":"10.7566/jpsj.93.034003","DOIUrl":"https://doi.org/10.7566/jpsj.93.034003","url":null,"abstract":"Multidimensional measurements and a cohesive interpretation of the obtained results are imperative for comprehending the underlying mechanisms of physical phenomena. In this dissertation, we propose the utilization of Bayesian integration as a method for obtaining a consolidated interpretation of results, based on Bayesian inference. We focus on 4<i>f</i> electron systems, which can be comprehended through the use of a relatively simple Hamiltonian. The measurements performed center on fundamental macroscopic properties: magnetic susceptibility and specific heat. We conduct simulations utilizing data obtained from two distinct measurements, namely magnetic susceptibility and specific heat, and demonstrate that the implementation of Bayesian integration enhances precision.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"20 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139926410","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}

{"title":"Feasibility Study of Thin Film Surface Analysis Using Synchrotron Low-Angle Incidence Conversion Electron Mössbauer Spectroscopy","authors":"Takaya Mitsui, Kosuke Fujiwara, Ko Mibu, Ryo Masuda, Yasuhiro Kobayashi, Makoto Seto","doi":"10.7566/jpsj.93.034705","DOIUrl":"https://doi.org/10.7566/jpsj.93.034705","url":null,"abstract":"A feasibility study was conducted on thin film surface analysis using conversion electron Mössbauer spectroscopy (CEMS) measured at incident angles more than the critical angle and less than several degrees, utilizing a synchrotron Mössbauer source. To identify the minimum incident angle yielding a CEMS spectrum with experimentally negligible nuclear specular reflection effects, γ-ray reflection and CEMS of a ⁵⁷Fe [90%] enriched thin film were studied by grazing-incidence synchrotron Mössbauer spectroscopy, varying the incident angle in the range of 0.3 to 3°. Since the incident angles were larger than the critical angle (<i>θ</i>_c ∼ 0.22°) of the iron film for 14.4 keV X-rays, the photons passing through the nuclear resonant channel, rather than the electronic non-resonant channel, predominantly contributed to the specular reflection. Consequently, at <i>θ</i>_in = 0.3°, strong scattering peaks appeared at nuclear resonance energies, and then CEMS showed an anomalous spectral profile. At <i>θ</i>_in &gt; <i>θ</i>_c, the nuclear specular reflection gradually decreased with increasing <i>θ</i>_in, whereas nuclear resonance peaks were persistently observed up to <i>θ</i>_in = 1.5°. Finally, the reflection signals were nearly extinguished at around <i>θ</i>_in = 3°, and the CEMS showed an experimentally normal spectral profile in usual use. Low-angle incidence CEMS with negligible nuclear specular reflection is advantageous for surface analysis of thin films because the penetration depth of γ-rays is still shorter than the conversion electron escape depth. Furthermore, a surface analysis of an annealed ⁵⁷Fe-rich film was conducted using low-angle incidence CEMS with circularly polarized synchrotron Mössbauer source. The present paper also describes the theoretical background and additional benefits in instrument development.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"34 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139926411","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}

{"title":"Low-Lying and Core Excited Doublet States of Lithium Atom in Various Plasma Environments","authors":"Salah Doma, Gamal Roston, Mostafa Ahmed","doi":"10.7566/jpsj.93.034301","DOIUrl":"https://doi.org/10.7566/jpsj.93.034301","url":null,"abstract":"New study is made for the impact of three different plasma potentials on the low-lying and core excited doublet states of the lithium atom using the variational Monte Carlo method. The considered low-lying excited doublet states include the states: 1<i>s</i>²<i>ns</i>, 1<i>s</i>²<i>np</i>, and 1<i>s</i>²<i>nd</i>, whereas the core excited states include the states: 1<i>s</i> <i>n</i>₁<i>l</i>₁<i>n</i>₁<i>l</i>₂ and 1<i>s</i> <i>n</i>₁<i>l</i>₁<i>n</i>₂<i>l</i>₂. Also, the three used plasma potentials are: screened Coulomb, exponential cosine screened Coulomb, and Hulthén potentials. The energy eigenvalues of the excited states are evaluated freely and under the influence of the plasma potentials using suitable trial wave functions including the spin and the correlated (electron–electron repulsion) parts. In addition, a suggested effective-plasma factor is considered in the wave function regarding the exponential cosine screened Coulomb potential model due to the dense plasma particle interactions. Interesting relative ordering of eigenvalues is reported for the excited states of the lithium atom corresponding to the three different screened Coulomb potentials.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"300 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139902675","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}

{"title":"Transition of the Bifurcations in the Rotation of a Camphor-Coated Elliptical Paper Disk","authors":"Michiko Shimokawa, Junma Arimitsu, Hiroyuki Kitahata, Hidetsugu Sakaguchi","doi":"10.7566/jpsj.93.034002","DOIUrl":"https://doi.org/10.7566/jpsj.93.034002","url":null,"abstract":"An elliptical camphor-coated paper disk whose center of mass is fixed at the rotational axis rotates spontaneously with a constant angular velocity when placed on the surface of water. In our experiments, we observed bifurcation by controlling the water depth, i.e., the disk rotated and was stationary at higher and lower water depths, respectively. Further, the bifurcation type depended on the aspect ratio of the elliptical camphor disk; subcritical and supercritical bifurcations were observed in the high- and low-aspect-ratio experiments, respectively. Thus, the experiments and phenomenological models indicated that the friction between the acrylic rod as the rotational axis and the center pore of the disk penetrated by the rod determined the bifurcation type.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"197 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751153","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}

{"title":"Magnetic Order Induced by the Cooperation of Valence and Structural Instabilities in Eu1−xCaxCo2P2","authors":"Kodai Moriyama, Kohei Yoshinaga, Ryoichiro Matsui, Chishiro Michioka, Hiroaki Ueda, Kazuyoshi Yoshimura","doi":"10.7566/jpsj.93.033702","DOIUrl":"https://doi.org/10.7566/jpsj.93.033702","url":null,"abstract":"Magnetism of layered compound Eu₁₋<i>_x</i>Ca<i>_x</i>Co₂P₂ was investigated by means of magnetization, specific heat, and electrical resistivity measurements. It is found that Eu undergoes a phase transition from a divalent state to a mixed-valence state of Eu²⁺<i>^δ</i> and Eu⁽³⁻<i>^δ</i>^′)+ simultaneously with a structural transition from the uncollapsed tetragonal (ucT) phase to the collapsed tetragonal (cT) phase near <i>x</i> = 0.5. Whereas the compounds with the ucT structure exhibit antiferromagnetic ordering of Eu²⁺ moments, those with the cT structure exhibit additional magnetic ordering of Co moments. The ordering temperature of Co moments is much higher than those in other <i>A</i>Co₂P₂ systems with a divalent <i>A</i> cation. These results suggest that an electron-doping effect on Co 3<i>d</i> bands owing to the Eu valence transition stabilizes the magnetic ordering of Co moments.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"98 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751248","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}

{"title":"Effective Tight-Binding Model of Compensated Ferrimagnetic Weyl Semimetal with Spontaneous Orbital Magnetization","authors":"Tomonari Meguro, Akihiro Ozawa, Koji Kobayashi, Kentaro Nomura","doi":"10.7566/jpsj.93.034703","DOIUrl":"https://doi.org/10.7566/jpsj.93.034703","url":null,"abstract":"The effective tight-binding model with compensated ferrimagnetic inverse-Heusler lattice Ti₂MnAl, candidate material of magnetic Weyl semimetal, is proposed. The energy spectrum near the Fermi level, the configurations of the Weyl points, and the anomalous Hall conductivity are calculated. We found that the orbital magnetization is finite, while the total spin magnetization vanishes, at the energy of the Weyl points. The magnetic moments at each site are correlated with the orbital magnetization and can be controlled by the external magnetic field.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"2 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751247","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}

{"title":"Deriving Quantum Spin Model for a Zigzag-Chain Ytterbium Magnet with Anisotropic Exchange Interactions","authors":"Hidehiro Saito, Hiroki Nakai, Chisa Hotta","doi":"10.7566/jpsj.93.034701","DOIUrl":"https://doi.org/10.7566/jpsj.93.034701","url":null,"abstract":"We derive a quantum spin Hamiltonian of the spin-1/2 zigzag chain realized in a rare earth ytterbium-based magnetic insulator, YbCuS₂. This material undergoes a transition at 0.95 K to an incommensurate magnetic phase with small moments, which does not conform to the prediction of nonmagnetic singlet ground state of the spin-1/2 Heisenberg model. We take account of octahedral crystal field effect, atomic spin–orbit coupling, and strong Coulomb interactions on Yb ions, and perform a fourth-order perturbation theory to evaluate the superexchange coupling constants. A small but finite anisotropic exchange coupling called Γ-term appears similarly to the case reported previously in other triangular-based magnets. By varying several material parameters, we figure out two important factors to enhance the Γ-term. One is the splitting of excited <i>f</i>-states with two holes, which efficiently selects the perturbation terms associated with the lowest excited state having large total angular momentum, and accordingly with high spatial anisotropy. The other is the tilting of octahedra or distortion of S–Yb–S bond angle, which breaks the symmetry of the Slater–Koster overlap. These effects are systematically analyzed by focusing on the anisotropy of exchange interactions between two spins using the local axis frame, which reduces the complexity of dealing with the bulk Hamiltonian described in a global axis frame.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139656667","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}