Physical Review Materials最新文献

{"title":"Structural stability of tungsten nanoparticles","authors":"L. Pizzagalli, S. Brochard, J. Godet, J. Durinck","doi":"10.1103/physrevmaterials.8.086001","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.086001","url":null,"abstract":"Motivated by contradicting reports in the literature, we have investigated the structural stability of tungsten nanoparticles using density functional theory calculations. The comparison of BCC, FCC, A15, disordered, and icosahedral configurations unequivocally shows that BCC is, energetically, the most stable structure when the number of atoms is greater than 40. A disordered structure is more stable for smaller sizes. This result conflicts with an earlier theoretical study on transition metal nanoparticles, based on a semi-empirical modeling of nanoparticles energetics [D. Tománek <i>et al.</i>, <span>Phys. Rev. B</span> <b>28</b>, 665 (1983)]. Examining this latter work in the light of our results suggests that an inappropriate description of cluster geometry is the source of the discrepancy. Finally, we improve the accuracy of the semi-empirical model proposed in this work, which will be useful to calculate nanoparticle energies for larger sizes.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"45 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of biquadratic magnetic exchange interaction in the 2D antiferromagnets MPS3 (M=Mn,Fe,Co,Ni)","authors":"M. Amirabbasi, P. Kratzer","doi":"10.1103/physrevmaterials.8.084005","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084005","url":null,"abstract":"The two-dimensional van der Waals (vdW) materials <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>M</mi><msub><mi>PS</mi><mn>3</mn></msub><mspace width=\"0.16em\"></mspace><mrow><mo>(</mo><mi>M</mi><mo>=</mo><mi>Mn</mi><mo>,</mo><mi>Fe</mi><mo>,</mo><mi>Co</mi><mo>,</mo><mi>Ni</mi><mo>)</mo></mrow></mrow></math> display antiferromagnetic ordering of the magnetic moments at the transition metal ions. The possibility to exfoliate thin layers that preserve the magnetic order makes these materials interesting for numerous applications in devices that require integration of flexible patches of magnetic materials, e.g., in antiferromagnetic spintronics. Hence, an improved understanding of their magnetic properties is desirable. Here, we parametrize spin Hamiltonians for a monolayer of all four materials of this class using density functional theory plus Hubbard <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>U</mi></math> calculations. We provide a step-by-step guide for calculating the magnetic exchange interactions and magnetic anisotropy energy using the (non)collinear <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>DFT</mi><mo>+</mo><mi>U</mi><mo>(</mo><mo>+</mo><mi>SOC</mi><mo>)</mo></mrow></math> approach with a suitably chosen <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>U</mi></math> for each material. It is found that the biquadratic interactions gain in importance while moving through the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3</mn><mi>d</mi></mrow></math> series. Retaining the leading terms of a Holstein-Primakoff-transformed spin Hamiltonian, the magnon spectra are calculated. While <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MnPS</mi><mn>3</mn></msub></math> is found to be an almost isotropic antiferromagnet with a tiny gap, the biquadratic interaction opens an increasingly wider gap for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>FePS</mi><mn>3</mn></msub><mo>,</mo><mo> </mo><msub><mi>CoPS</mi><mn>3</mn></msub></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>NiPS</mi><mn>3</mn></msub></math>. In line with this observation, Monte Carlo simulations demonstrate that the biquadratic interactions contribute to a systematic rise in the Néel temperature from <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>FePS</mi><mn>3</mn></msub></math> to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>NiPS</mi><mn>3</mn></msub></math>.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"57 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lattice dynamics study of electron-correlation-induced charge density wave in antiferromagnetic kagome metal FeGe","authors":"Andrzej Ptok, Surajit Basak, Aksel Kobiałka, Małgorzata Sternik, Jan Łażewski, Paweł T. Jochym, Andrzej M. Oleś, Przemysław Piekarz","doi":"10.1103/physrevmaterials.8.l080601","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.l080601","url":null,"abstract":"Electron-correlation-driven phonon soft modes have been recently reported in the antiferromagnetic kagome FeGe compound and associated with the observed charge density wave (CDW). In this paper, we present a systematic investigation of the CDW origin in the context of the <i>ab initio</i> lattice dynamics study. Performing the group theory analysis of the aforementioned soft modes, we found that the stable structure has the Immm symmetry and can be achieved by shifts of Ge atoms. The occurrence of two soft modes induces the first-order phase transition, which leads to the CDW order. Additionally, we show that the final structure realizes a distorted honeycomb Ge lattice, as well as a nonflat kagome-like Fe net. For completeness, we present the electronic properties calculations. From the theoretical STM topography simulation, we indicate that the observed CDW occurs in the deformed honeycomb Ge sublattice.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"10 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Excitonic trion population in two-dimensional halide perovskites","authors":"Efstratios Manousakis","doi":"10.1103/physrevmaterials.8.084004","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084004","url":null,"abstract":"There are many reports of a surprisingly high charge-carrier density with sizable mobility in photoexcited two-dimensional (2D) halide perovskites despite their unusually high exciton binding energy. In this work we study the thermodynamic quasiequilibrium of the relative population of photoexcited free quasielectron/quasihole pairs, neutral excitons, and excitonic trions, in 2D materials that support such excitonic complexes with large binding energy. We derive and solve the general Saha equations which describe the detailed balance of such a system of photoexcited electronic degrees of freedom forming a multicomponent fluid of excitations in thermodynamic quasiequilibrium. The solution to these equations, for the special case of 2D perovskites where the reported exciton and excitonic trion binding energies are of the order of 0.3–0.4 eV for the former and 30–40 meV for the latter, reveals that while the charge-neutral excitonic population dominates all other excitations, at room temperature and below, the excitonic trion component can be the dominant population among charge carriers. We also argue that trionic hopping can take place via a tunneling mechanism which is speculated to play a role in a novel charge-transport mechanism.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"13 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unbiased screening of deep-ultraviolet and mid-infrared nonlinear optical crystals: Long-neglected covalent and mixed-cation motifs","authors":"Jizhang Wang, Meng Ye, Xiaomi Guo, Yang Li, Nianlong Zou, He Li, Zetao Zhang, Sibo Zhao, Zhiming Xu, Haowei Chen, Dezhao Wu, Ting Bao, Yong Xu, Wenhui Duan","doi":"10.1103/physrevmaterials.8.085202","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085202","url":null,"abstract":"One of the most important nonlinear optical (NLO) effects is the second-harmonic generation (SHG), and crystals with strong SHG effects are called NLO crystals. The traditional anion group theory has guided the early discovery of NLO crystals, but the variety of NLO-active motifs discovered so far is limited. In this study, material-type unbiased high-throughput first-principles calculations are performed to screen thousands of materials in a materials database for NLO crystals at target frequencies. The electronic, linear, and nonlinear optical properties of these materials are calculated. Among them, 40 NLO crystals suitable for mid-infrared (MIR) frequencies and 5 for deep-ultraviolet (DUV) frequencies are identified, from 229 materials to which scissors correction is applied. As an extension, several NLO-active motifs that dominate the SHG response are identified, and they all show good transferability among similar materials. Furthermore, for materials where scissors correction cannot be applied due to the lack of accurate bandgap value in the database, a recommendation list of NLO crystals based on the scaling law of bandgap and SHG susceptibility is presented. The discovery of new NLO crystals and NLO-active motifs beyond traditional methods will greatly accelerate the applications of NLO crystals at DUV and MIR frequencies and enrich our understanding in the search and design of new NLO crystals.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"16 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ce2Ir3Ga5 : A new locally noncentrosymmetric heavy fermion system","authors":"Arushi, Raul Cardoso-Gil, Christoph Geibel","doi":"10.1103/physrevmaterials.8.085001","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085001","url":null,"abstract":"Recently, a new type of unconventional superconductivity with a field-induced transition between two different superconducting (SC) states was discovered in the heavy fermion system <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>CeRh</mi><mn>2</mn></msub><msub><mi>As</mi><mn>2</mn></msub></mrow></math>. This unusual SC state was proposed to be based on specific symmetries of the underlying structure, i.e., a globally centrosymmetric layered structure, but where the Ce layers themselves lack inversion symmetry. This new type of SC state has attracted strong interest, prompting the search for further heavy fermion systems crystallizing in structures with appropriate symmetries. We report the discovery and the study of a new Ce-based heavy fermion system with a globally centrosymmetric structure but without inversion symmetry on the Ce-site, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Ce</mi><mn>2</mn></msub><msub><mi>Ir</mi><mn>3</mn></msub><msub><mi>Ga</mi><mn>5</mn></msub></mrow></math>. A single crystal x-ray diffraction study revealed an orthorhombic <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi mathvariant=\"normal\">U</mi><mn>2</mn></msub><msub><mi>Co</mi><mn>3</mn></msub><msub><mi>Si</mi><mn>5</mn></msub></mrow></math> type structure. Resistivity, specific heat, and magnetization measurements indicate a moderate-heavy fermion behavior with a Kondo energy scale of the order of 40 K. Most experimental results suggest the absence of magnetic order, but a tiny anomaly in the specific heat opens the possibility for a very weak, itinerant type of ordering.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"8 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Raman scattering study of crystal field excitations in Co-based quantum magnets","authors":"Banasree S. Mou, Xinshu Zhang, Li Xiang, Yuanyuan Xu, Ruidan Zhong, Robert J. Cava, Haidong Zhou, Zhigang Jiang, Dmitry Smirnov, Natalia Drichko, Stephen M. Winter","doi":"10.1103/physrevmaterials.8.084408","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084408","url":null,"abstract":"Co-based materials have recently been explored because of their potential to realize complex bond-dependent anisotropic magnetism. Prominent examples include <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Na</mi><mn>2</mn></msub><msub><mi>Co</mi><mn>2</mn></msub><msub><mi>TeO</mi><mn>6</mn></msub></mrow><mo>,</mo><mo> </mo><mrow><msub><mi>BaCo</mi><mn>2</mn></msub><msub><mrow><mo>(</mo><msub><mi>AsO</mi><mn>4</mn></msub><mo>)</mo></mrow><mn>2</mn></msub></mrow><mo>,</mo><mo> </mo><mrow><msub><mi>Na</mi><mn>2</mn></msub><mi>BaCo</mi><msub><mrow><mo>(</mo><msub><mi>PO</mi><mn>4</mn></msub><mo>)</mo></mrow><mn>2</mn></msub></mrow></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mrow><mi>Co</mi><mi mathvariant=\"italic\">X</mi></mrow><mn>2</mn></msub></math> <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>(</mo><mi>X</mi><mo>=</mo><mi>Cl</mi><mo>,</mo><mi>Br</mi><mo>,</mo><mi mathvariant=\"normal\">I</mi><mo>)</mo></mrow></math>. In order to provide insight into the magnetic interactions in these compounds, we make a comparative analysis of their local crystal electric field excitations spectra via Raman scattering measurements. Combining these measurements with theoretical analysis confirms the validity of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>j</mi><mi>eff</mi></msub><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math> single-ion ground states for all compounds, and provides accurate experimental estimates of the local crystal distortions, which play a prominent role in the magnetic couplings between spin-orbital coupled Co moments.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"2 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic ordering of the Mo3O8-type cluster Mott insulator Na3Sc2(MoO4)2Mo3O8 with spin-1/2 triangular lattice prepared via optimal synthesis","authors":"Yuya Haraguchi, Daigo Ishikita, Hiroko Aruga Katori","doi":"10.1103/physrevmaterials.8.084409","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084409","url":null,"abstract":"We detail the optimized synthesis of the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mo&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;O&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;-type cluster Mott insulator (CMI) &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Na&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Sc&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;MoO&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Mo&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;O&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;, which has been considered a candidate for realizing the spin liquid ground state. The optimized &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Na&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Sc&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;MoO&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Mo&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;O&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;, characterized by x-ray diffraction, energy-dispersive x-ray spectroscopy, and magnetic and heat capacity measurements exhibited an effective magnetic moment close to the ideal 1.73 &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi mathvariant=\"normal\"&gt;B&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt; for S = 1/2 spin and magnetic ordering at ∼5 K. These observations categorize &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Na&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Sc&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;MoO&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Mo&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;O&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt; as the second &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mo&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;O&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;-type CMI to achieve a magnetic ground state, following &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;Li&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;InMo&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;O&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;. They highlight the stabilization of the magnetic ground state over the theoretically anticipated quantum spin liquid state through precise valence and chemical disorder tuning. Our findings challenge the existing theory that the magnetic ground state of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mo&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;O&lt;/mi&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;-type CMIs is determined by the breathing parameter, instead showing that magnetic order is suppressed by spin defects. This study underscores the crucial role of chemical precision in investigating quantum magnetism. It suggests that precise tuning of valence states could induce magnetic ordering in pre","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"18 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct evidence of induced magnetic moment in Se and the role of misplaced Mn in MnBi2Se4-based intrinsic magnetic topological insulator heterostructures","authors":"R. Fukushima, V. N. Antonov, M. M. Otrokov, T. T. Sasaki, R. Akiyama, K. Sumida, K. Ishihara, S. Ichinokura, K. Tanaka, Y. Takeda, D. P. Salinas, S. V. Eremeev, E. V. Chulkov, A. Ernst, T. Hirahara","doi":"10.1103/physrevmaterials.8.084202","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084202","url":null,"abstract":"Intrinsic magnetic topological insulators, in which magnetism and topology are inherently combined, are excellent systems to realize exotic phenomena such as the quantum anomalous Hall effect. However, there are many reports that show that the experimental samples are not so ideal and the effect of the unintentional disorder in these systems needs to be considered carefully. In this study, we investigate the role of misplaced magnetic atoms as well as nonmagnetic elements in the intrinsic magnetic topological insulator heterostructures based on <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>MnBi</mi><mn>2</mn></msub><msub><mi>Se</mi><mn>4</mn></msub></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Se</mi><mn>3</mn></msub></mrow></math>. We find that Mn atoms are not only placed at the central layer of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>MnBi</mi><mn>2</mn></msub><msub><mi>Se</mi><mn>4</mn></msub></mrow></math> septuple layer (SL) but also intermix with Bi (antisite Mn) as well as reside in the van der Waals (vdW) gap. Through a detailed comparison between the experimental and theoretical x-ray magnetic circular dichroism (XMCD) spectra, we find that the antisite Mn is coupled ferromagnetically, whereas the vdW Mn couple antiferromagnetically to the Mn in the central atomic plane of the SL. Furthermore, we detect a clear XMCD signal in nonmagnetic Se, providing unambiguous evidence of its magnetic interaction with Mn.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"22 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoelectric transport in Weyl semimetal BaMnSb2: A first-principles study","authors":"Yubi Chen, Rongying Jin, Bolin Liao, Sai Mu","doi":"10.1103/physrevmaterials.8.085401","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085401","url":null,"abstract":"Topological materials are often associated with exceptional thermoelectric properties. Orthorhombic <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ba</mi><mi>Mn</mi><msub><mi>Sb</mi><mn>2</mn></msub></mrow></math> is a topological semimetal consisting of alternating layers of Ba, Sb, and MnSb. A recent experiment demonstrates that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ba</mi><mi>Mn</mi><msub><mi>Sb</mi><mn>2</mn></msub></mrow></math> has a low thermal conductivity and modest thermopower, promising as a thermoelectric material. Through first-principles calculations with Coulomb repulsion and spin-orbit coupling included, we studied the electronic structure, phononic structure, and thermoelectric transport properties of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ba</mi><mi>Mn</mi><msub><mi>Sb</mi><mn>2</mn></msub></mrow></math> in depth. We find that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ba</mi><mi>Mn</mi><msub><mi>Sb</mi><mn>2</mn></msub></mrow></math> exhibits a low lattice thermal conductivity, owing to the scattering of the acoustic phonons with low-frequency optical modes. Using the linearized Boltzmann transport theory with a constant relaxation time approximation, the thermopower is further calculated and an intriguing goniopolar transport behavior, which is associated with both <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi></math>-type and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-type conduction along separate transport directions simultaneously, is observed. We propose that the figure of merit can be enhanced via doping in which electrical conductivity is increased while the thermopower remains undiminished. <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ba</mi><mi>Mn</mi><msub><mi>Sb</mi><mn>2</mn></msub></mrow></math> is a potential platform for elucidating complex band structure effects and topological phenomena, paving the way to explore rich physics in low-dimensional systems.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"61 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}