Pub Date : 2024-10-09DOI: 10.1016/j.mtquan.2024.100017
Juyoung Jeong , Yongwoo Lee , Shi-Zeng Lin , Yoon Hee Jeong , Hye Jung Chang , Jeehoon Kim
Skyrmions, highly mobile and manipulable magnetic objects, have garnered significant interest for their potential applications in modern magnetic device technology. However, their formation has been limited to a small number of materials due to the delicate balance of magnetic energies involved. In this study, we report the irreversible formation of skyrmions in Nd2Fe14B, a rare-earth permanent magnet characterized by large magnetic anisotropy. Remarkably, these magnetic topological defects exist over a wide range of temperatures and magnetic fields (295–565 K and 0–0.1 T) due to the high Curie temperature and significant magnetic anisotropy of Nd2Fe14B. Our findings not only unveil a new material where skyrmions can form but also open up possibilities for exploring topological defects in various magnetic systems, including strong hard magnets.
Skyrmions 是一种高度移动和可操控的磁性物体，因其在现代磁性器件技术中的潜在应用而备受关注。然而，由于涉及磁能的微妙平衡，它们的形成仅限于少数材料。在这项研究中，我们报告了在钕2铁14B中不可逆地形成天顶子的情况，钕2铁14B是一种稀土永磁体，具有较大的磁各向异性。值得注意的是，由于 Nd2Fe14B 的居里温度高且磁各向异性显著，这些磁拓扑缺陷存在于很宽的温度和磁场范围内（295-565 K 和 0-0.1 T）。我们的发现不仅揭示了一种可以形成天幕的新材料，而且为探索包括强硬磁体在内的各种磁性系统中的拓扑缺陷提供了可能性。
{"title":"Topological magnetic defects in a strong permanent magnet Nd2Fe14B","authors":"Juyoung Jeong , Yongwoo Lee , Shi-Zeng Lin , Yoon Hee Jeong , Hye Jung Chang , Jeehoon Kim","doi":"10.1016/j.mtquan.2024.100017","DOIUrl":"10.1016/j.mtquan.2024.100017","url":null,"abstract":"<div><div>Skyrmions, highly mobile and manipulable magnetic objects, have garnered significant interest for their potential applications in modern magnetic device technology. However, their formation has been limited to a small number of materials due to the delicate balance of magnetic energies involved. In this study, we report the irreversible formation of skyrmions in Nd<sub>2</sub>Fe<sub>14</sub>B, a rare-earth permanent magnet characterized by large magnetic anisotropy. Remarkably, these magnetic topological defects exist over a wide range of temperatures and magnetic fields (295–565 K and 0–0.1 T) due to the high Curie temperature and significant magnetic anisotropy of Nd<sub>2</sub>Fe<sub>14</sub>B. Our findings not only unveil a new material where skyrmions can form but also open up possibilities for exploring topological defects in various magnetic systems, including strong hard magnets.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"4 ","pages":"Article 100017"},"PeriodicalIF":0.0,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.mtquan.2024.100018
Pingping Liu , Lu Fu , Gerile Aodeng , Lu Ga , Jun Ai
Boron-Sulfur-Nitrogen doped carbon dots (B, N, S-CDs) were prepared by a simple hydrothermal method using 2-Mercaptopyrimidine (C4H4N2S) and citric acid (C6H8N7•H2O) as raw materials. The B, N, S-CDs showed exceptional fluorescence response to Fe2+, TC. The results of the B, N, S-CDs are very promising for the detection of real water samples. In addition, the B, N, S-CDs had a good temperature response (reversible and recoverable fluorescence in the temperature range of 25–65︒C). The low cytotoxicity and in vitro cellular imaging properties exhibited by this carbon dot also greatly enhance their utility.
{"title":"Synthesis of temperature-sensitive boron, nitrogen and sulphur doped carbon dots and their applications","authors":"Pingping Liu , Lu Fu , Gerile Aodeng , Lu Ga , Jun Ai","doi":"10.1016/j.mtquan.2024.100018","DOIUrl":"10.1016/j.mtquan.2024.100018","url":null,"abstract":"<div><div>Boron-Sulfur-Nitrogen doped carbon dots (B, N, S-CDs) were prepared by a simple hydrothermal method using 2-Mercaptopyrimidine (C<sub>4</sub>H<sub>4</sub>N<sub>2</sub>S) and citric acid (C<sub>6</sub>H<sub>8</sub>N<sub>7</sub>•H<sub>2</sub>O) as raw materials. The B, N, S-CDs showed exceptional fluorescence response to Fe<sup>2+</sup>, TC. The results of the B, N, S-CDs are very promising for the detection of real water samples. In addition, the B, N, S-CDs had a good temperature response (reversible and recoverable fluorescence in the temperature range of 25–65︒C). The low cytotoxicity and in vitro cellular imaging properties exhibited by this carbon dot also greatly enhance their utility.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"4 ","pages":"Article 100018"},"PeriodicalIF":0.0,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1016/j.mtquan.2024.100016
H. Suriya Arachchige , L.M. DeBeer-Schmitt , L.L. Kish , Binod K. Rai , A.F. May , D.S. Parker , G. Pokharel , Wei Tian , Matthew B. Stone , Matthias Frontzek , D.G. Mandrus , M. Bleuel , Z. Islam , G. Fabbris , H.X. Li , S. Gao , H. Miao , S.M. Thomas , P.F.S. Rosa , J.D. Thompson , A.D. Christianson
The rare earth neodymium arguably exhibits the most complex magnetic ordering and series of magnetic phase transitions of the elements. Here we report the results of small-angle neutron scattering (SANS) measurements as a function of temperature and applied magnetic field to study magnetic correlations on nanometer length scales in Nd. We support these results with additional neutron diffraction, thermodynamic and synchrotron x-ray measurements. The SANS measurements reveal the presence of modulation vectors characterizing the ordered spin configuration which exhibit changes in magnitude and direction that are phase dependent. Between 5.9 and 7.6 K an additional modulation vector is observed with magnitude = 0.12 Å −1. This scattering appears to originate from order of the Nd layers which contain a center of inversion. Tracking this modulation vector as a function of magnetic field indicates a phase boundary at 1 T. The modulation vectors observed in this study establish the presence of nanometer length scale spin textures which are likely stabilized by frustrated Ruderman–Kittel–Kasuya–Yosida (RKKY) interactions.
稀土钕可以说是磁排序和磁相变系列最复杂的元素。在此，我们报告了小角中子散射（SANS）测量结果与温度和外加磁场的函数关系，以研究钕中纳米长度尺度的磁相关性。我们还通过中子衍射、热力学和同步辐射 X 射线测量来支持这些结果。SANS 测量揭示了有序自旋构型的调制矢量特征，其大小和方向的变化与相位有关。在 5.9 至 7.6 K 之间，还观察到一个额外的调制矢量，其大小为 Q = 0.12 Å-1。这种散射似乎源自包含反转中心的钕层。这项研究中观察到的调制矢量确定了纳米级自旋纹理的存在，这种纹理很可能是通过受挫的 Ruderman-Kittel-Kasuya-Yosida (RKKY) 相互作用而稳定下来的。
{"title":"Nanometric modulations of the magnetic structure of the element Nd","authors":"H. Suriya Arachchige , L.M. DeBeer-Schmitt , L.L. Kish , Binod K. Rai , A.F. May , D.S. Parker , G. Pokharel , Wei Tian , Matthew B. Stone , Matthias Frontzek , D.G. Mandrus , M. Bleuel , Z. Islam , G. Fabbris , H.X. Li , S. Gao , H. Miao , S.M. Thomas , P.F.S. Rosa , J.D. Thompson , A.D. Christianson","doi":"10.1016/j.mtquan.2024.100016","DOIUrl":"10.1016/j.mtquan.2024.100016","url":null,"abstract":"<div><div>The rare earth neodymium arguably exhibits the most complex magnetic ordering and series of magnetic phase transitions of the elements. Here we report the results of small-angle neutron scattering (SANS) measurements as a function of temperature and applied magnetic field to study magnetic correlations on nanometer length scales in Nd. We support these results with additional neutron diffraction, thermodynamic and synchrotron x-ray measurements. The SANS measurements reveal the presence of modulation vectors characterizing the ordered spin configuration which exhibit changes in magnitude and direction that are phase dependent. Between 5.9 and 7.6 K an additional modulation vector is observed with magnitude <span><math><mi>Q</mi></math></span> = 0.12 Å <sup>−1</sup>. This scattering appears to originate from order of the Nd layers which contain a center of inversion. Tracking this modulation vector as a function of magnetic field indicates a phase boundary at <span><math><mo>≈</mo></math></span>1 T. The modulation vectors observed in this study establish the presence of nanometer length scale spin textures which are likely stabilized by frustrated Ruderman–Kittel–Kasuya–Yosida (RKKY) interactions.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"4 ","pages":"Article 100016"},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.mtquan.2024.100015
Geng-Dong Zhou , Yi-Jie Wang , Wen-Xuan Wang , Xiao-Bo Lu , Zhi-Da Song
Motivated by recent experimental observations of displacement-field-tuned correlated insulators at integer and half-integer fillings in chirally twisted triple bilayer graphene (CTTBG) [Phys.Rev.Lett.132.246501], we study the single-particle and interacting physics of CTTBG. We find that there are two inequivalent stacking orders, i.e., AB-AB-BC and AB-AB-AB, and both exhibit flat bands with nontrivial topology. We then use the Hartree–Fock approximation to calculate the rich phase diagram of CTTBG at all integer and half-integer fillings in both stacking orders and under the vertical displacement field. Under a small displacement field, the groundstates are flavor polarized states for AB-AB-BC stacking order and intervalley coherent states for AB-AB-AB stacking order at all integer and half-integer fillings. A larger displacement field will turn them into layer-polarized states. At half-integer fillings, the groundstates also exhibit charge density wave (CDW) order. For AB-AB-AB stacking, the groundstates at half-integer fillings are always 2 × 1 stripe state among a range of displacement fields. For AB-AB-BC stacking, the groundstates at half-integer fillings are also 2 × 1 stripe states under a small displacement field and a larger displacement will possibly favor further translation-symmetry-breaking, depending on filling and the direction of the displacement field. We demonstrate that the CDW states observed in the experiment can originate from the strong Coulomb interaction of the flat band electrons.
{"title":"Correlated insulators and charge density wave states in chirally twisted triple bilayer graphene","authors":"Geng-Dong Zhou , Yi-Jie Wang , Wen-Xuan Wang , Xiao-Bo Lu , Zhi-Da Song","doi":"10.1016/j.mtquan.2024.100015","DOIUrl":"10.1016/j.mtquan.2024.100015","url":null,"abstract":"<div><div>Motivated by recent experimental observations of displacement-field-tuned correlated insulators at integer and half-integer fillings in chirally twisted triple bilayer graphene (CTTBG) [<span><span>Phys.Rev.Lett.132.246501</span><svg><path></path></svg></span>], we study the single-particle and interacting physics of CTTBG. We find that there are two inequivalent stacking orders, <em>i.e.</em>, AB-AB-BC and AB-AB-AB, and both exhibit flat bands with nontrivial topology. We then use the Hartree–Fock approximation to calculate the rich phase diagram of CTTBG at all integer and half-integer fillings in both stacking orders and under the vertical displacement field. Under a small displacement field, the groundstates are flavor polarized states for AB-AB-BC stacking order and intervalley coherent states for AB-AB-AB stacking order at all integer and half-integer fillings. A larger displacement field will turn them into layer-polarized states. At half-integer fillings, the groundstates also exhibit charge density wave (CDW) order. For AB-AB-AB stacking, the groundstates at half-integer fillings are always 2 × 1 stripe state among a range of displacement fields. For AB-AB-BC stacking, the groundstates at half-integer fillings are also 2 × 1 stripe states under a small displacement field and a larger displacement will possibly favor further translation-symmetry-breaking, depending on filling and the direction of the displacement field. We demonstrate that the CDW states observed in the experiment can originate from the strong Coulomb interaction of the flat band electrons.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"4 ","pages":"Article 100015"},"PeriodicalIF":0.0,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study evaluates the efficacy of quantum machine learning (QML) models in predicting stainless steel corrosion behaviour. Using two datasets, the quantum support vector classifier (QSVC) outperformed classical models, achieving accuracies of 95.46 % and 94.80 % for Dataset A and Dataset B, respectively. The QSVC excelled in identifying complex corrosion classes and demonstrated robust performance across diverse environments. This QML approach accurately predicts corrosion without experimental testing, saving significant time and cost. Future research will aim to include more environmental variables and steel types, broadening the model's applicability.
本研究评估了量子机器学习（QML）模型在预测不锈钢腐蚀行为方面的功效。利用两个数据集，量子支持向量分类器（QSVC）的表现优于经典模型，数据集 A 和数据集 B 的准确率分别达到 95.46 % 和 94.80 %。QSVC 在识别复杂的腐蚀类别方面表现出色，并在不同环境下表现出稳健的性能。这种 QML 方法无需实验测试即可准确预测腐蚀，从而节省了大量时间和成本。未来的研究将致力于纳入更多的环境变量和钢材类型，从而扩大模型的适用性。
{"title":"Quantum machine learning for corrosion resistance in stainless steel","authors":"Muhamad Akrom , Supriadi Rustad , Totok Sutojo , De Rosal Ignatius Moses Setiadi , Hermawan Kresno Dipojono , Ryo Maezono , Moses Solomon","doi":"10.1016/j.mtquan.2024.100013","DOIUrl":"10.1016/j.mtquan.2024.100013","url":null,"abstract":"<div><p>This study evaluates the efficacy of quantum machine learning (QML) models in predicting stainless steel corrosion behaviour. Using two datasets, the quantum support vector classifier (QSVC) outperformed classical models, achieving accuracies of 95.46 % and 94.80 % for Dataset A and Dataset B, respectively. The QSVC excelled in identifying complex corrosion classes and demonstrated robust performance across diverse environments. This QML approach accurately predicts corrosion without experimental testing, saving significant time and cost. Future research will aim to include more environmental variables and steel types, broadening the model's applicability.</p></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"3 ","pages":"Article 100013"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2950257824000131/pdfft?md5=2dbe1782598f260eba88f00b35e603ac&pid=1-s2.0-S2950257824000131-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142094774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<div><p>The layer-polarized anomalous Hall effect has emerged as a novel phenomenon in the field of condensed matter physics, holding significant promise for future applications in designing low-dissipation devices. Currently, the layer-polarized anomalous Hall effect has been theoretically predicted or experimentally demonstrated through the application of external electric fields or the utilization of sliding ferroelectricity in diverse systems. Here, through first-principles calculations, we propose a pathway to realize the layer-polarized anomalous Hall effect by constructing A-type antiferromagnetic topological insulator MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> based heterostructures with ferroelectric materials In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>. Our results firstly show that the sizeable band splitting (larger than 20 meV) appears in the antiferromagnetic 4 septuple layers MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> system due to broken inversion symmetry. Further calculations approve that the layer-polarized anomalous Hall conductivity with reversal signs can be observed in the antiferromagnetic 4 septuple layers MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> (In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) systems by shifting the Fermi energy level. Additionally, it is also found that ferrimagnetic 4 septuple layers MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> (In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) can be realized by controlling the direction of ferroelectric polarization of ferroelectric materials. Thus, the resulting layer-polarized anomalous Hal
{"title":"Layer-polarized anomalous Hall effect in the MnBi2Te4/In2Se3 (In2Te3) heterostructures","authors":"Hong Xu, Xuqi Li, Haidan Sang, Yu Zhang, Wenying Mu, Shifei Qi","doi":"10.1016/j.mtquan.2024.100012","DOIUrl":"10.1016/j.mtquan.2024.100012","url":null,"abstract":"<div><p>The layer-polarized anomalous Hall effect has emerged as a novel phenomenon in the field of condensed matter physics, holding significant promise for future applications in designing low-dissipation devices. Currently, the layer-polarized anomalous Hall effect has been theoretically predicted or experimentally demonstrated through the application of external electric fields or the utilization of sliding ferroelectricity in diverse systems. Here, through first-principles calculations, we propose a pathway to realize the layer-polarized anomalous Hall effect by constructing A-type antiferromagnetic topological insulator MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> based heterostructures with ferroelectric materials In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>. Our results firstly show that the sizeable band splitting (larger than 20 meV) appears in the antiferromagnetic 4 septuple layers MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> system due to broken inversion symmetry. Further calculations approve that the layer-polarized anomalous Hall conductivity with reversal signs can be observed in the antiferromagnetic 4 septuple layers MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> (In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) systems by shifting the Fermi energy level. Additionally, it is also found that ferrimagnetic 4 septuple layers MnBi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Se<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> (In<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) can be realized by controlling the direction of ferroelectric polarization of ferroelectric materials. Thus, the resulting layer-polarized anomalous Hal","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"3 ","pages":"Article 100012"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S295025782400012X/pdfft?md5=56d493650688f0da73b3e5e4c7112299&pid=1-s2.0-S295025782400012X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142094775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 10.1016/j.mtquan.2024.100014
Ping Lu , Xiangru Hou , Lu Ga , Gerile Aodeng , Jun Ai
Carbon quantum dots (CQDs) are widely used in optical biosensors due to their good biocompatibility and easy synthesis type. Although the carbon sources for preparing CQDs are quite extensive, it is not common to prepare CQDs using herbs as carbon sources. Therefore, CQDs for fluorescence determination of Fe3+ and dopamine (DA) were prepared by microwave heating using senna leaf as carbon source. The prepared CQDs showed good dispersion and uniform sphericity under transmission electron microscopy (TEM), with an average particle size of 3.510 nm. Under ultraviolet light, CQDs fluoresce brightly blue and have a strong fluorescence (>1.200*103 a.u.), with no change in fluorescence intensity over a week. The prepared CQDs were quenched by Fe3+ and DA probably due to the static burst effect, which can be confirmed by X-ray photoelectron spectroscopy (XPS) and fourier-transform infrared spectroscopy (FT-IR) analyses. The method has a good linear relationship for Fe3+ in the range of 10–3000 μmol/L with a determination limit of 0.1671 μmol/L, and an excellent linear relationship for DA in the range of 5–3000 μmol/L with a determination limit of 0.1653 μmol/L. The method was applied to the determination of Fe3+ and DA in real samples, and the recovery rate was satisfactory.
{"title":"Senna-based carbon quantum dots as probes for the determination of Fe3+ and dopamine","authors":"Ping Lu , Xiangru Hou , Lu Ga , Gerile Aodeng , Jun Ai","doi":"10.1016/j.mtquan.2024.100014","DOIUrl":"10.1016/j.mtquan.2024.100014","url":null,"abstract":"<div><p>Carbon quantum dots (CQDs) are widely used in optical biosensors due to their good biocompatibility and easy synthesis type. Although the carbon sources for preparing CQDs are quite extensive, it is not common to prepare CQDs using herbs as carbon sources. Therefore, CQDs for fluorescence determination of Fe<sup>3+</sup> and dopamine (DA) were prepared by microwave heating using senna leaf as carbon source. The prepared CQDs showed good dispersion and uniform sphericity under transmission electron microscopy (TEM), with an average particle size of 3.510 nm. Under ultraviolet light, CQDs fluoresce brightly blue and have a strong fluorescence (>1.200*10<sup>3</sup> a.u.), with no change in fluorescence intensity over a week. The prepared CQDs were quenched by Fe<sup>3+</sup> and DA probably due to the static burst effect, which can be confirmed by X-ray photoelectron spectroscopy (XPS) and fourier-transform infrared spectroscopy (FT-IR) analyses. The method has a good linear relationship for Fe<sup>3+</sup> in the range of 10–3000 μmol/L with a determination limit of 0.1671 μmol/L, and an excellent linear relationship for DA in the range of 5–3000 μmol/L with a determination limit of 0.1653 μmol/L. The method was applied to the determination of Fe<sup>3+</sup> and DA in real samples, and the recovery rate was satisfactory.</p></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"3 ","pages":"Article 100014"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2950257824000143/pdfft?md5=2f99c1aa0ced4ec7038f7255994e795e&pid=1-s2.0-S2950257824000143-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1016/j.mtquan.2024.100011
Rajendra Subedi , Francisco Ruiz-Zepeda , Qiaohui Zhou , Xin Lu , Grégory Guisbiers
Quantum dots are semiconductor nanoparticles where electrons’ motion is confined within the three physical dimensions of the nanoparticle, such that discretization of energy levels is observed. In this article, quantum dots of Bi2Te3, with sizes around 9 ± 2 nm and energy bandgap around ∼ 2.8 eV, were successfully synthesized by pulsed laser ablation in liquids. Those dots were found to be within the strong confinement regime.
量子点是一种半导体纳米粒子，电子的运动被限制在纳米粒子的三个物理维度内，从而观察到能级的离散化。本文在液体中通过脉冲激光烧蚀成功合成了尺寸约为 9 ± 2 nm、能带隙约为∼ 2.8 eV 的 Bi2Te3 量子点。研究发现，这些点处于强约束状态。
{"title":"Synthesis of strongly confined Bi2Te3 quantum dots by pulsed laser ablation in liquids","authors":"Rajendra Subedi , Francisco Ruiz-Zepeda , Qiaohui Zhou , Xin Lu , Grégory Guisbiers","doi":"10.1016/j.mtquan.2024.100011","DOIUrl":"10.1016/j.mtquan.2024.100011","url":null,"abstract":"<div><p>Quantum dots are semiconductor nanoparticles where electrons’ motion is confined within the three physical dimensions of the nanoparticle, such that discretization of energy levels is observed. In this article, quantum dots of Bi<sub>2</sub>Te<sub>3</sub>, with sizes around 9 ± 2 nm and energy bandgap around ∼ 2.8 eV, were successfully synthesized by pulsed laser ablation in liquids. Those dots were found to be within the strong confinement regime.</p></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"3 ","pages":"Article 100011"},"PeriodicalIF":0.0,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2950257824000118/pdfft?md5=afbc86d67682813fabc58b44b380c138&pid=1-s2.0-S2950257824000118-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142075926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-17DOI: 10.1016/j.mtquan.2024.100010
Satoru Hayami , Ryota Yambe
Multiple- states as represented by a magnetic skyrmion crystal and hedgehog crystal have been extensively studied in recent years owing to their unconventional physical properties. The materials hosting multiple- states have been so far observed in a variety of lattice structures and chemical compositions, which indicates rich stabilization mechanisms inducing the multiple- states. We review recent developments in the research of the stabilization mechanisms of such multiple- states with an emphasis on the microscopic spin interactions in momentum space. We show that an effective momentum-resolved spin model is a canonical model for not only understanding the microscopic origin of various multiple- states but also exploring further exotic multiple- states with topological properties. We introduce several key ingredients to realize the magnetic skyrmion crystal with the skyrmion numbers of one and two, hedgehog crystal, meron–antimeron crystal, bubble crystal, and other multiple- states. We also review that the effective spin model can be used to reproduce the magnetic phase diagram in experiments efficiently.
{"title":"Stabilization mechanisms of magnetic skyrmion crystal and multiple-Q states based on momentum-resolved spin interactions","authors":"Satoru Hayami , Ryota Yambe","doi":"10.1016/j.mtquan.2024.100010","DOIUrl":"10.1016/j.mtquan.2024.100010","url":null,"abstract":"<div><p>Multiple-<span><math><mi>Q</mi></math></span> states as represented by a magnetic skyrmion crystal and hedgehog crystal have been extensively studied in recent years owing to their unconventional physical properties. The materials hosting multiple-<span><math><mi>Q</mi></math></span> states have been so far observed in a variety of lattice structures and chemical compositions, which indicates rich stabilization mechanisms inducing the multiple-<span><math><mi>Q</mi></math></span> states. We review recent developments in the research of the stabilization mechanisms of such multiple-<span><math><mi>Q</mi></math></span> states with an emphasis on the microscopic spin interactions in momentum space. We show that an effective momentum-resolved spin model is a canonical model for not only understanding the microscopic origin of various multiple-<span><math><mi>Q</mi></math></span> states but also exploring further exotic multiple-<span><math><mi>Q</mi></math></span> states with topological properties. We introduce several key ingredients to realize the magnetic skyrmion crystal with the skyrmion numbers of one and two, hedgehog crystal, meron–antimeron crystal, bubble crystal, and other multiple-<span><math><mi>Q</mi></math></span> states. We also review that the effective spin model can be used to reproduce the magnetic phase diagram in experiments efficiently.</p></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"3 ","pages":"Article 100010"},"PeriodicalIF":0.0,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2950257824000106/pdfft?md5=93373e393eed686b303bb92293c4950c&pid=1-s2.0-S2950257824000106-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142020885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.1016/j.mtquan.2024.100009
Lijun Liu , Xiangru Hou , Gerile Aodeng , Lu Ga , Jun Ai
Since the accidental discovery of carbon quantum dots (CQDs) in 2004, they have been widely used in the field of fluorescence sensing by combining their good optical and physicochemical properties with a wide source of raw materials and a simple synthesis process. In this work, we have synthesised sulphur-doped carbon quantum dots L-CyS/AA CQDs by a one-step microwave method using L-cysteine (L-CyS) and ascorbic acid (AA) as carbon and sulphur sources. It was also analysed by fluorescence spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The prepared L-CyS/AA CQDs showed good dispersion under TEM with a spherical shape and an average particle size of 7.3 nm. L-CyS/AA CQDs were observed to be bright blue-green fluorescent with strong fluorescence (>3.5*103 a.u.) under UV light irradiation. PASS 0 logic gate operation can be achieved by controlling different fluorescent input and output. L-CyS/AA CQDs were able to achieve selective detection of Co2+ with a LOD of 63.2 μM, which provides a new method for Co2+ detection that can be used for the detection of Co2+ in real water samples.
{"title":"Selective detection of Co2+ by L-CyS/AA CQDs and Construction of PASS 0 gate","authors":"Lijun Liu , Xiangru Hou , Gerile Aodeng , Lu Ga , Jun Ai","doi":"10.1016/j.mtquan.2024.100009","DOIUrl":"10.1016/j.mtquan.2024.100009","url":null,"abstract":"<div><p>Since the accidental discovery of carbon quantum dots (CQDs) in 2004, they have been widely used in the field of fluorescence sensing by combining their good optical and physicochemical properties with a wide source of raw materials and a simple synthesis process. In this work, we have synthesised sulphur-doped carbon quantum dots L-CyS/AA CQDs by a one-step microwave method using L-cysteine (L-CyS) and ascorbic acid (AA) as carbon and sulphur sources. It was also analysed by fluorescence spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The prepared L-CyS/AA CQDs showed good dispersion under TEM with a spherical shape and an average particle size of 7.3 nm. L-CyS/AA CQDs were observed to be bright blue-green fluorescent with strong fluorescence (>3.5*10<sup>3</sup> a.u.) under UV light irradiation. PASS 0 logic gate operation can be achieved by controlling different fluorescent input and output. L-CyS/AA CQDs were able to achieve selective detection of Co<sup>2+</sup> with a LOD of 63.2 μM, which provides a new method for Co<sup>2+</sup> detection that can be used for the detection of Co<sup>2+</sup> in real water samples.</p></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"3 ","pages":"Article 100009"},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S295025782400009X/pdfft?md5=69c523d235651d9819015fb90c361e78&pid=1-s2.0-S295025782400009X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141848720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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