The European Physical Journal B最新文献_第10页

An experimental study of the static magnetic properties of Co thin films 钴薄膜静磁特性的实验研究

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-25 DOI: 10.1140/epjb/s10051-024-00729-w

A. Kharmouche

{"title":"An experimental study of the static magnetic properties of Co thin films","authors":"A. Kharmouche","doi":"10.1140/epjb/s10051-024-00729-w","DOIUrl":"10.1140/epjb/s10051-024-00729-w","url":null,"abstract":"<div><p>Thermal heating process has been used, under a pressure of 10<sup>−7</sup> mbar, to deposit thin films of cobalt onto monocrystalline silicon substrate. The incident beam strikes the substrates under normal incidence. The thickness ranges from 50 to 400 nm. To investigate the static magnetic properties, the hysteresis loops are performed by means of alternating gradient field magnetometer device. The zero-field magnetic structure has been investigated by magnetic force microscopy (MFM) technique, using a Veeco 3100 apparatus. MFM images reveal well-defined stripe patterns, mainly for the thickest films, which infer the dominance of the magnetocrystalline anisotropy. The easy magnetization axis lies within the plane of the film with a small component out-of-the plane for the thicker films. Coercivity evolution versus thickness follows a <i>t</i><sup>−<i>n</i></sup> Néel law, characteristic of Bloch domain wall motion. In addition, it was found that coercivity depends plainly on the surface roughness of the films.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>AFM (left) and MFM (right) images of Co thin films, with different thickness, (<b>a</b>) 100 nm, (<b>b</b>) 300 nm, (<b>c</b>) 400 nm. Scan area is 20 µm × 20 µm</p></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527914","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}

引用次数: 0

The impact of different unravelings in a monitored system of free fermions 自由费米子监控系统中不同解离的影响

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-25 DOI: 10.1140/epjb/s10051-024-00725-0

Giulia Piccitto, Davide Rossini, Angelo Russomanno

{"title":"The impact of different unravelings in a monitored system of free fermions","authors":"Giulia Piccitto, Davide Rossini, Angelo Russomanno","doi":"10.1140/epjb/s10051-024-00725-0","DOIUrl":"10.1140/epjb/s10051-024-00725-0","url":null,"abstract":"<p>We consider a free-fermion chain undergoing dephasing, described by two different random-measurement protocols (unravelings): a quantum-state-diffusion and a quantum-jump one. Both protocols keep the state in a Slater-determinant form, allowing to address quite large system sizes. We find a bifurcation in the distribution of the measurement operators along the quantum trajectories, that’s to say, there is a point where the shape of this distribution changes from unimodal to bimodal. The value of the measurement strength where this phenomenon occurs is similar for the two unravelings, but the distributions and the transition have different properties reflecting the symmetries of the two measurement protocols. We also consider the scaling with the system size of the inverse participation ratio of the Slater-determinant components and find a power-law scaling that marks a multifractal behaviour, in both unravelings and for any nonvanishing measurement strength.</p><p>Position of the maxima of <i>P</i> <i>n</i> vs <span>(gamma )</span> for the QSD protocol. The two maxima stem continuously and symmetrically at the bifurcation point <span>(gamma )</span> QSD <span>(sim 0.2)</span>, with a discontinuity of the derivative.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00725-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Entanglement detection in postquench nonequilibrium states: thermal Gibbs vs. generalized Gibbs ensemble 淬火后非平衡态中的纠缠探测：热吉布斯与广义吉布斯集合

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-25 DOI: 10.1140/epjb/s10051-024-00715-2

Ferenc Iglói, Csaba Zoltán Király

引用次数: 0

Non-Hermitian tearing by dissipation 非赫米撕裂耗散

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-24 DOI: 10.1140/epjb/s10051-024-00714-3

Qian Du, Xin-Ran Ma, Su-Peng Kou

引用次数: 0

Effects of ballistic transport on the thermal resistance and temperature profile in nanowires 弹道传输对纳米线热阻和温度曲线的影响。

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-24 DOI: 10.1140/epjb/s10051-024-00727-y

R. Meyer, Graham W. Gibson, Alexander N. Robillard

引用次数: 0

Differential equation for the Uehling potential 厄林电势微分方程

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-22 DOI: 10.1140/epjb/s10051-024-00728-x

Alexei M. Frolov

引用次数: 0

Revisiting the Thomas–Fermi potential for three-dimensional condensed matter systems 重新审视三维凝聚态系统的托马斯-费米势

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-21 DOI: 10.1140/epjb/s10051-024-00711-6

Gionni Marchetti

{"title":"Revisiting the Thomas–Fermi potential for three-dimensional condensed matter systems","authors":"Gionni Marchetti","doi":"10.1140/epjb/s10051-024-00711-6","DOIUrl":"10.1140/epjb/s10051-024-00711-6","url":null,"abstract":"<p>We proposed a formally exact, probabilistic method to assess the validity of the Thomas–Fermi potential for three-dimensional condensed matter systems where electron dynamics is constrained to the Fermi surface. Our method, which relies on accurate solutions of the radial Schrödinger equation, yields the probability density function for momentum transfer. This allows for the computation of its expectation values, which can be compared with unity to confirm the validity of the Thomas–Fermi approximation. We applied this method to three <i>n</i>-type direct-gap III–V model semiconductors (GaAs, InAs, InSb) and found that the Thomas–Fermi approximation is certainly valid at high electron densities. In these cases, the probability density function exhibits the same profile, irrespective of the material under scrutiny. Furthermore, we show that this approximation can lead to serious errors in the computation of observables when applied to GaAs at zero temperature for most electron densities under scrutiny.</p><p>The Thomas-Fermi potential <span>(V_textrm{ei}^textrm{TF}left( rright) )</span> and the the exponential cosine screened Coulomb potential <span>(V_textrm{ei}^textrm{EC}left( rright) )</span> in coordinate space <i>r</i>, from the full interaction potential <span>(V_textrm{ei}^textrm{RPA}left( qright) )</span> in the momentum space <i>q</i> at Random Phase approximation, through suitable Fourier transforms</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527919","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}

引用次数: 0

Kaniadakis entropy in extreme gravitational and cosmological environments: a review on the state-of-the-art and future prospects 极端引力和宇宙学环境中的卡尼达基斯熵：最新进展和未来展望综述

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-21 DOI: 10.1140/epjb/s10051-024-00730-3

Giuseppe Gaetano Luciano

引用次数: 0

Evaluation of photoluminescence and colorimetric performance of Tb3+-induced calcium tungstate ceramic Tb3+ 引发的钨酸钙陶瓷的光致发光和比色性能评估

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-21 DOI: 10.1140/epjb/s10051-024-00726-z

R. Paikaray, T. Badapanda, S. Sahoo, H. Mohapatra

{"title":"Evaluation of photoluminescence and colorimetric performance of Tb3+-induced calcium tungstate ceramic","authors":"R. Paikaray, T. Badapanda, S. Sahoo, H. Mohapatra","doi":"10.1140/epjb/s10051-024-00726-z","DOIUrl":"10.1140/epjb/s10051-024-00726-z","url":null,"abstract":"<div><p>Photoluminescence and colorimetric investigations of Ca<sub>1−<i>x</i></sub>Tb<sub>2<i>x</i>/3</sub>WO<sub>4</sub> with <i>x</i> vary from 0.01 to 0.05 samples made by employing the solid-state reaction routes are represented in this paper. Structural analyses of all the phosphors are done with the help of X-ray diffraction spectroscopy and denoted that they exhibit a tetragonal structure and <i>I4</i><sub><i>1</i></sub><i>/a</i> space group without containing any secondary phase. Optical properties are described with the help of the UV–visible reflectance spectra. In addition, the energy bandgap values are evaluated from these spectra and the values are increased concerning the rise in the Tb contents in CaWO<sub>4</sub>. Photoluminescence studies are done by considering PL excitation spectra as well as PL emission spectra. The critical concentration of quenching is observed at the composition <i>x</i> = 0.03 along with the critical distance of energy transfer is computed to be ~ 20 Å. Moreover, this distance is created by the dipole–dipole exchanges and indicated by the calculated <i>Q</i> value. Colorimetric analyses of the samples are done from the CIE color coordinates. The green emission color is obtained for all the materials. All the colorimetric parameters are evaluated and quantum yield efficiency for <i>x</i> = 0.03 Tb incorporated CaWO<sub>4</sub> material is obtained by exciting it with 485 nm wavelength. Average lifetime values are evaluated by analyzing the PL decay plots.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div><div><p>CIE chromaticity diagram of Tb-doped CaWO<sub>4</sub> at 485 nm EX wavelength</p></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527917","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}

引用次数: 0

Rare earth element Pr enables high thermoelectric performance of Cu12Sb4S13 稀土元素 Pr 实现了 Cu12Sb4S13 的高热电性能

IF 1.6 4区物理与天体物理

The European Physical Journal B Pub Date : 2024-06-21 DOI: 10.1140/epjb/s10051-024-00716-1

Chen Zhu, Feng Hu, Lei Jiang, Shouxi Jiang, Kun Ding, Jian Shao, Manman Ding, Fali Chong

{"title":"Rare earth element Pr enables high thermoelectric performance of Cu12Sb4S13","authors":"Chen Zhu, Feng Hu, Lei Jiang, Shouxi Jiang, Kun Ding, Jian Shao, Manman Ding, Fali Chong","doi":"10.1140/epjb/s10051-024-00716-1","DOIUrl":"10.1140/epjb/s10051-024-00716-1","url":null,"abstract":"<div><p>Cu<sub>12</sub>Sb<sub>4</sub>S<sub>13</sub> has received great attention due to its remarkable thermoelectric properties among medium-temperature range. Herein, the effect of rare earth element Pr substitution at Cu site of Cu<sub>12</sub>Sb<sub>4</sub>S<sub>13</sub> is comprehensively investigated. Heavy rare earth element Pr substitution can induce strong mass fluctuation and strain-field fluctuation, resulting in intense phonon scattering and decreased lattice thermal conductivity. Consequently, a low lattice thermal conductivity κ<sub>L</sub> of 0.42 W m<sup>−1</sup> K<sup>−1</sup> is obtained at 748 K in Cu<sub>11.7</sub>Pr<sub>0.3</sub>Sb<sub>4</sub>S<sub>13</sub> sample. Additionally, the substitution of Pr for Cu can function as donors, tuning the hole concentration and optimizing the thermopower over the entire temperature range, with a maximum thermopower of 165 μV K<sup>−1</sup> at 748 K. Correspondingly, a peak <i>ZT</i> of~0.9 is obtained at 748 K in Cu<sub>11.7</sub>Pr<sub>0.3</sub>Sb<sub>4</sub>S<sub>13</sub> sample, due to the significantly reduced thermal conductivity and slightly enhanced power factor.\u0000</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div><div><p>Perspective of Cu<sub>12</sub>Sb<sub>4</sub>S<sub>13</sub> crystal structure and the temperature-dependent ZT for Cu<sub>12-<i>x</i></sub>Pr<sub><i>x</i></sub>Sb<sub>4</sub>S<sub>13</sub> samples</p></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527916","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}

引用次数: 0