Physical Review Materials最新文献

{"title":"Surface phase diagram of CsSnI3 from first-principles calculations","authors":"Kejia Li, Chadawan Khamdang, Mengen Wang","doi":"10.1103/physrevmaterials.8.093401","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.093401","url":null,"abstract":"<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CsSnI</mi><mn>3</mn></msub></math> is widely studied as an environmentally friendly Pb-free perovskite material for optoelectronic device applications. To further improve material and device performance, it is important to understand the surface structures of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CsSnI</mi><mn>3</mn></msub></math>. We generate surface structures with various stoichiometries, perform density functional theory calculations to create phase diagrams of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CsSnI</mi><mn>3</mn></msub></math> (001), (110), and (100) surfaces, and determine the most stable surfaces under a wide range of Cs, Sn, and I chemical potentials. Under I-rich conditions, surfaces with Cs vacancies are stable, which lead to partially occupied surface states above the valence band maximum. Under I-poor conditions, we find the stoichiometric (100) surface to be stable under a wide region of the phase diagram, which does not have any surface states and can contribute to long charge-carrier lifetimes. Consequently, the I-poor (Sn-rich) conditions will be more beneficial to improve the device performance.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"149 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206145","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":"Layer dependent topological phases and transitions in TaRhTe4: From monolayer and bilayer to bulk","authors":"Xiao Zhang, Ning Mao, Oleg Janson, Jeroen van den Brink, Rajyavardhan Ray","doi":"10.1103/physrevmaterials.8.094201","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094201","url":null,"abstract":"The recently synthesized ternary quasi-2D material <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>TaRhTe</mi><mn>4</mn></msub></math> is a bulk Weyl semimetal with an intrinsically layered structure, which poses the question of how the topology of its electronic structure depends on layer separations. Experimentally, these separations may be changed for instance by intercalation of the bulk, or by exfoliation, to reach monolayer or few-layer structures. Here, we show that in the monolayer limit a quantum spin Hall insulator (QSHI) state emerges, employing density functional calculations as well as a minimal four-orbital tight-binding model that we develop. Even for weak spin-orbit couplings the QSHI is present, which has an interesting edge state that features Rashba-split bands with quadratic band minima. Further, we find that a weak topological insulator (WTI) manifests in the bilayer system due to sizable intralayer hopping, contrary to the common lore that only weak interlayer interactions between stacked QSHIs lead to WTIs. Stacked bilayers give rise to a phase diagram as a function of the interlayer separation that comprises a Weyl semimetal, WTI, and normal insulator (NI) phases. These insights on the evolution of topology with dimensions can be transferred to the family of layered ternary transition metal tellurides.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"10 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206117","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":"Optimizing the adsorption strength of oxygen intermediates on NiCo2O4 by Fe doping to improve the oxygen evolution reaction performance","authors":"Xilin Zhang, Rui Song, Yanyan Zhai, Rui Zheng, Shan Wang, Zhongjun Ma, Zongxian Yang","doi":"10.1103/physrevmaterials.8.095801","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.095801","url":null,"abstract":"Spinel oxide (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math>) is an attractive catalyst for oxygen evolution reaction (OER) due to its rich redox reactions and unique electronic structure. However, the electrocatalytic OER performance of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math> has always been limited by the low specific surface area and poor intrinsic conductivity of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math>. Cationic doping is an effective method in modulating the electrocatalytic activity at the atomic level to improve the conductivity and activity. Herein, a series of Fe-doped <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math> electrocatalysts were successfully prepared using a simple solvothermal method. Impressively, Fe-doped <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math> delivers an attractive small overpotential of 341 mV at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>10</mn><mspace width=\"0.28em\"></mspace><mi>mA</mi><mspace width=\"0.16em\"></mspace><mi mathvariant=\"normal\">c</mi><msup><mrow><mi mathvariant=\"normal\">m</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math> and a Tafel slope of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>74</mn><mspace width=\"0.28em\"></mspace><mi>mV</mi><mspace width=\"0.16em\"></mspace><mi>de</mi><msup><mrow><mi mathvariant=\"normal\">c</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> compared to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math>. The x-ray photoelectron spectroscopy and the density functional theory calculations reveal that Fe dopants can regulate the electronic structure of Ni sites by donating electrons to Co atoms, which leads to an increased <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">N</mi><msup><mrow><mi mathvariant=\"normal\">i</mi></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></mrow></math> ratio and a reduced adsorption strength of oxygen intermediates at Ni sites, thus facilitating the conversion of *OH to *O. This work provides an effective approach to enhancing the electrocatalytic activities of non-noble-metal-based catalysts.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"32 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206127","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":"Theoretical and experimental investigations on Fe2P-type magnets: Effects of Si and Co substitution on physical and magnetic properties","authors":"Stephan Erdmann, Halil İbrahim Sözen, Francois Guillou, Hargen Yibole, Thorsten Klüner","doi":"10.1103/physrevmaterials.8.094401","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094401","url":null,"abstract":"&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi mathvariant=\"normal\"&gt;P&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;-based magnets are known for their significant magnetic properties, making them useful in various technological applications. The aim of this study was to investigate the effects of Si and Co substitution on the physical and magnetic properties of the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi mathvariant=\"normal\"&gt;P&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; compounds. In order to have a systematic understanding we have performed combined &lt;i&gt;ab initio&lt;/i&gt; calculations and a set of experiments. Particular emphasis was placed on the study of preferential substitution sites, lattice constants, magnetic moments, and the Curie temperature (&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;), which was further explored by considering the exchange interaction energies &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;j&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;. Satisfactory agreement was observed between theoretical calculations and the predicted phase transition from the hexagonal to the body-centered-orthorhombic (BCO) crystal structure as a function of temperature. Theoretical calculations reveal that the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; position is the preferred site for Si, while Co is expected to occupy the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; sites. Theoretical analysis of the magnetic moments shows an increase up to &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;3.64&lt;/mn&gt;&lt;mspace width=\"0.16em\"&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mrow&gt;&lt;mi mathvariant=\"normal\"&gt;f&lt;/mi&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mi mathvariant=\"normal\"&gt;u&lt;/mi&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt; for &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; = 0.5 Si, which agrees with the experimental values of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;3.16&lt;/mn&gt;&lt;mspace width=\"0.16em\"&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mrow&gt;&lt;mi mathvariant=\"normal\"&gt;f&lt;/mi&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mi mathvariant=\"normal\"&gt;u&lt;/mi&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt; Co substitution in &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;Co&lt;/mi&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;P&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;0.84&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;Si&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;0.16&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt; and &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;Co&lt;/mi&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;P&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;0.59&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;Si&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;0.41&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt; resulted in a decrease in magnetic moments and consequently in other magnetic prope","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"180 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206118","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":"Bonding hierarchy and coordination interaction leading to high thermoelectricity in wide bandgap TlAgI2","authors":"Xiaoying Wang, Mengyang Li, Minxuan Feng, Xuejie Li, Yuzhou Hao, Wen Shi, Jiangang He, Xiangdong Ding, Zhibin Gao","doi":"10.1103/physrevmaterials.8.094601","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094601","url":null,"abstract":"High thermoelectric properties are associated with the phonon-glass electron-crystal paradigm. Conventional wisdom suggests that the optimal bandgap of semiconductor to achieve the largest power factor should be between 6 and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>10</mn><msub><mi>κ</mi><mi>B</mi></msub><mi>T</mi></mrow></math>. To address challenges related to the bipolar effect and temperature limitations, we present findings on Zintl-type <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>TlAgI</mi><mn>2</mn></msub></math>, which demonstrates an exceptionally low lattice thermal conductivity of 0.30 W <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mrow><mi mathvariant=\"normal\">m</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mspace width=\"4pt\"></mspace><msup><mrow><mi mathvariant=\"normal\">K</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> at 300 K. The achieved figure of merit (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Z</mi><mi>T</mi></mrow></math>) for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>TlAgI</mi><mn>2</mn></msub></math>, featuring a 2.40 eV bandgap, reaches a value of 1.53 for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-type semiconductor. This remarkable <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Z</mi><mi>T</mi></mrow></math> is attributed to the existence of extended antibonding states [Ag-I] in the valence band. Furthermore, the bonding hierarchy, influencing phonon anharmonicity, and coordination bonds, facilitating electron transfer between the ligand and the central metal ion, significantly contribute to the electronic transport. This finding serves as a promising avenue for the development of high <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Z</mi><mi>T</mi></mrow></math> materials with wide bandgaps at elevated temperatures.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"7 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206121","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":"Continuous structural phase transition and antiferromagnetic order in ilmenite-type NiVO3","authors":"Hajime Yamamoto, Osamu Ikeda, Takashi Honda, Kenta Kimura, Takuya Aoyama, Kenya Ohgushi, Akio Suzuki, Kenji Ishii, Daiju Matsumura, Takuya Tsuji, Shintaro Kobayashi, Shogo Kawaguchi, Matteo d’Astuto, Tadashi Abukawa","doi":"10.1103/physrevmaterials.8.094402","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094402","url":null,"abstract":"We investigate the crystal and electronic structures as well as magnetic properties of ilmenite-type <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math>, which has attracted research interest as an <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>S</mi></mrow></math> = 1 honeycomb lattice magnet. Ilmenite-type <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> samples were synthesized under high-pressure and high-temperature conditions. Synchrotron x-ray diffraction and Rietveld refinement results demonstrated that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> underwent a continuous structural phase transition from the triclinic (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>P</mi></mrow><mover accent=\"true\"><mn>1</mn><mo>¯</mo></mover></math>) phase to the rhombohedral (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>R</mi></mrow><mover accent=\"true\"><mn>3</mn><mo>¯</mo></mover></math>) phase at 450 K. This transition is concomitant with the decomposition of the V-V dimers formed by the tetravalent V ions. X-ray absorption spectroscopy measurements confirmed that the Ni and V ions were divalent and tetravalent, respectively. Magnetic and specific heat measurements revealed that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> underwent an antiferromagnetic transition at 140 K, and a zigzag-type magnetic order with magnetic propagation vector <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>k</mi><mo>=</mo><mo>(</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>/</mo><mn>2</mn><mo>,</mo><mn>0</mn><mo>)</mo></mrow></math> was observed by neutron diffraction measurements.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"32 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206129","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 anisotropy in single-crystalline antiferromagnetic Mn2Au","authors":"Mebatsion S. Gebre, Rebecca K. Banner, Kisung Kang, Kejian Qu, Huibo Cao, André Schleife, Daniel P. Shoemaker","doi":"10.1103/physrevmaterials.8.084413","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084413","url":null,"abstract":"Multiple recent studies have identified the metallic antiferromagnet &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; to be a candidate for spintronic applications due to apparent in-plane anisotropy, preserved magnetic properties above room temperature, and current-induced Néel vector switching. Crystal growth is complicated by the fact that &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; melts incongruently. We present a bismuth flux method to grow millimeter-scale bulk single crystals of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; in order to examine the intrinsic anisotropic electrical and magnetic properties. Flux quenching experiments reveal that the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; crystals precipitate below &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;550&lt;/mn&gt;&lt;msup&gt;&lt;mspace width=\"0.16em\"&gt;&lt;/mspace&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/msup&gt;&lt;mi mathvariant=\"normal\"&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;, about &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;100&lt;/mn&gt;&lt;msup&gt;&lt;mspace width=\"0.16em\"&gt;&lt;/mspace&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/msup&gt;&lt;mi mathvariant=\"normal\"&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; below the decomposition temperature of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;. Bulk &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; crystals have a room-temperature resistivity of 16–19 &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mi&gt;µ&lt;/mi&gt;&lt;mi mathvariant=\"normal\"&gt;Ω&lt;/mi&gt;&lt;mspace width=\"0.16em\"&gt;&lt;/mspace&gt;&lt;mi&gt;cm&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; and a residual resistivity ratio of 41. &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; crystals have a dimensionless susceptibility on the order of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt; (SI units), comparable to calculated and experimental reports on powder samples. Single-crystal neutron diffraction confirms the in-plane magnetic structure. The tetragonal symmetry of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;Mn&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; constrains the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;-plane magnetic susceptibility to be constant, meaning that &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;mn&gt;100&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;mn&gt;110&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt; in the low-field limit, below any spin-flop transition. We find that three measured magnetic susceptibilities &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;mn&gt;100&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;msub","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"11 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206120","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":"Optical absorption study of iron-substituted zirconia and yttria-stabilized zirconia using experimental measurements and many-body perturbation theory","authors":"Shunshun Liu, Victor K. Champagne, III, David R. Clarke, Prasanna V. Balachandran","doi":"10.1103/physrevmaterials.8.085203","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085203","url":null,"abstract":"Yttria-stabilized zirconia (YSZ) coatings have been developed for high temperature energy applications including gas turbines. The objective of this work is to understand how aliovalent Fe substitution affects the optical absorption spectrum of the host YSZ and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>ZrO</mi><mn>2</mn></msub></math> systems in the ultraviolet–visible–near infrared wavelength range (from 245 to 2500 nm) using both experimental and computational techniques. In the Fe-substituted <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>ZrO</mi><mn>2</mn></msub></math> system, phase-pure (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>&gt;</mo><mn>99</mn></math>% purity) samples were synthesized in the monoclinic crystal structure, whereas Fe substitution in YSZ resulted in a two-phase mixture of coexisting tetragonal and monoclinic phases. Optical property characterization performed at room temperature revealed two broad absorption bands in both systems: one centered around 1000 nm and the other centered around 500 nm. Tauc plot analysis of the optical absorption data showed that as the Fe concentration increases, the optical band gaps of both materials systems decrease. Many-body perturbation theory methods, based on <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>G</mi><mn>0</mn></msub><msub><mi>W</mi><mn>0</mn></msub></mrow></math> and the Bethe-Salpeter equation, were used to computationally model the optical absorption spectrum as a function of Fe substitution in the tetragonal and monoclinic crystal structures of YSZ and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>ZrO</mi><mn>2</mn></msub></math>. Supercells were constructed and several Fe- and/or Y-atom configurations were explored in Zr sites. Charge compensating O vacancies were introduced to maintain electrical neutrality. The computations reveal that the observed optical excitations centered around 1000 nm likely have an excitonic character due to defect states, whose origin is traced to the electronic transitions between <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Fe</mi><mtext>−</mtext><mn>3</mn><mi>d</mi></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Fe</mi><mtext>−</mtext><mn>3</mn><mi>d</mi></mrow></math> orbitals. Intriguingly, both the tetragonal and monoclinic crystal structures appear to support local polyhedral distortions that promote excitations in the 1000 nm wavelength region. The excitation centered around 500 nm is attributed to the optical band gap of these materials. The outcomes of this work shed light on the radiative properties of Fe-substituted YSZ with implications in thermal barrier coating composition design.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"21 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226373","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":"High mobility charge transport in a multicarrier altermagnet CrSb","authors":"Takahiro Urata, Wataru Hattori, Hiroshi Ikuta","doi":"10.1103/physrevmaterials.8.084412","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084412","url":null,"abstract":"A newly identified magnetic phase called altermagnet is being actively studied because of its unprecedented spin-dependent phenomena. Among the candidate materials, CrSb has a particularly high ordering temperature and a large spin-splitting energy, but its transport properties have remained unexplored. In this study, we report the magnetotransport properties of CrSb measured on single crystals. We found that the Hall resistivity shows a nonlinear dependence on the magnetic field at low temperatures. From symmetry-based considerations, however, this behavior cannot be attributed to an anomalous Hall effect, but to a multicarrier effect. A multicarrier fitting to the in-plane conductivity tensor revealed the presence of carriers with high mobility in CrSb, which is an advantage for efficient spin current generation.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226374","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":"Point defects in CdTe and CdTeSe alloy: A first principles investigation with DFT+U","authors":"Xiaofeng Xiang, Yijun Tong, Aaron Gehrke, Scott T. Dunham","doi":"10.1103/physrevmaterials.8.084602","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084602","url":null,"abstract":"CdTe and its alloy CdSeTe are widely used in optoelectronic devices, such as radiation detectors and solar cells, due to their superior electrical properties. However, the formation of defects and defect complexes in these materials can significantly affect their performance. As a result, understanding the defect formation and recombination processes in CdTe and CdSeTe alloy is of great importance. In recent years, density functional theory (DFT) calculations have emerged as a powerful tool for investigating the properties of defects in semiconductors. In this paper, we use <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>DFT</mi><mo>+</mo><mi mathvariant=\"normal\">U</mi></mrow></math> calculations to comprehensively study the properties of intrinsic defects as well as extrinsic defects induced by commonly used dopants, such as Cu and group V elements, in CdTe and CdSeTe alloy. This work provides insights into the effects of these defects on the electrical and optical properties of the material.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"33 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206128","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}