Physical Review Materials最新文献

{"title":"Low-energy modeling of three-dimensional topological insulator nanostructures","authors":"Eduárd Zsurka, Cheng Wang, Julian Legendre, Daniele Di Miceli, Llorenç Serra, Detlev Grützmacher, Thomas L. Schmidt, Philipp Rüßmann, Kristof Moors","doi":"10.1103/physrevmaterials.8.084204","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084204","url":null,"abstract":"We develop an accurate nanoelectronic modeling approach for realistic three-dimensional topological insulator nanostructures and investigate their low-energy surface-state spectrum. Starting from the commonly considered four-band <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">k</mi><mo>·</mo><mi mathvariant=\"normal\">p</mi></mrow></math> bulk model Hamiltonian for the <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> family of topological insulators, we derive new parameter sets for <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><mo>,</mo><mo> </mo><mrow><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>3</mn></msub><mo>,</mo></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Sb</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>3</mn></msub></mrow></math>. We consider a fitting strategy applied to <i>ab initio</i> band structures around the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">Γ</mi></math> point that ensures a quantitatively accurate description of the low-energy bulk and surface states while avoiding the appearance of unphysical low-energy states at higher momenta, something that is not guaranteed by the commonly considered perturbative approach. We analyze the effects that arise in the low-energy spectrum of topological surface states due to band anisotropy and electron-hole asymmetry, yielding Dirac surface states that naturally localize on different side facets. In the thin-film limit, when surface states hybridize through the bulk, we resort to a thin-film model and derive thickness-dependent model parameters from <i>ab initio</i> calculations that show good agreement with experimentally resolved band structures, unlike the bulk model that neglects relevant many-body effects in this regime. Our versatile modeling approach offers a reliable starting point for accurate simulations of realistic topological material-based nanoelectronic devices.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"61 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226375","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":"Ultrahigh stability of oxygen sublattice in β−Ga2O3","authors":"Ru He, Junlei Zhao, Jesper Byggmästar, Huan He, Flyura Djurabekova","doi":"10.1103/physrevmaterials.8.084601","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084601","url":null,"abstract":"Recently reported remarkably high radiation tolerance of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>γ</mi><mo>/</mo><mi>β</mi><mtext>−</mtext><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> double-polymorphic structure brings this ultrawide-band-gap semiconductor to the frontiers of power electronics applications that are able to operate in challenging environments. Understanding the mechanism of radiation tolerance is crucial for further material modification and tailoring of the desired properties. In this study, we employ machine-learning-enhanced atomistic simulations to assess the stability of both the gallium (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>Ga</mi></math>) and oxygen (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math>) sublattices under various levels of damage. Our study uncovers the remarkable resilience and stability of the -sublattice, attributing this property to the strong tendency of recovery of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math> defects, especially within the more strongly disordered regions. Interestingly, we observe the opposite behavior of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>Ga</mi></math> defects that display enhanced stability in the same regions of increased disorder. Moreover, we observe that highly defective <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>β</mi><mtext>−</mtext><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> is able to transform into <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>γ</mi><mtext>−</mtext><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> upon annealing due to preserved lattice organization of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math> sublattice. This result clearly manifests that the ultrahigh stability of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math> sublattice provides the backbone for the exceptional radiation tolerance of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>γ</mi><mo>/</mo><mi>β</mi></mrow></math> double-polymorphic structure. These computational insights closely align with experimental observations, opening avenues for further exploration of polymorphism in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> and potentially in analogous polymorphic families spanning a broad range of diverse materials of complex polymorphic nature.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"7 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226376","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 phase dependency of the thermal conductivity of FeRh from thermoreflectance experiments and numerical simulations","authors":"A. Castellano, K. Alhada-Lahbabi, J. A. Arregi, V. Uhlíř, B. Perrin, C. Gourdon, D. Fournier, M. J. Verstraete, L. Thevenard","doi":"10.1103/physrevmaterials.8.084411","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084411","url":null,"abstract":"FeRh is well known in its bulk form for a temperature-driven antiferromagnetic (AFM) to ferromagnetic (FM) transition near room temperature. It has aroused renewed interest in its thin-film form, with particular focus on its biaxial AFM magnetic anisotropy which could serve for data encoding, and the possibility to investigate laser-assisted phase transitions, with varying contributions from electrons, phonons, and magnons. In order to estimate the typical temperature increase occurring in these experiments, we performed modulated thermoreflectance microscopy to determine the thermal conductivity <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>κ</mi></math> of FeRh. As often occurs upon alloying, and despite the good crystallinity of the layer, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>κ</mi></math> was found to be lower than the thermal conductivities of its constituting elements. More unexpectedly, given the electrically more conducting nature of the FM phase, it turned out to be three times lower in the FM phase compared to the AFM phase. This trend was confirmed by examining the temporal decay of incoherent phonons generated by a pulsed laser in both phases. To elucidate these results, first- and second-principles simulations were performed to estimate the phonon, magnon, and electron contributions to the thermal conductivity. They were found to be of the same order of magnitude, and to give a quantitative rendering of the experimentally observed <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>κ</mi><mi>AFM</mi></msub></math>. In the FM phase, however, simulations overestimate the low experimental values, implying very different (shorter) electron and magnon lifetimes.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"2 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206131","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":"Single crystal growth, chemical defects, magnetic and transport properties of antiferromagnetic topological insulators (Ge1−δ−xMnx)2Bi2Te5 (x≤0.47, 0.11≤δ≤0.20)","authors":"Tiema Qian, Chaowei Hu, J. Green, Erxi Feng, Huibo Cao, Ni Ni","doi":"10.1103/physrevmaterials.8.084203","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084203","url":null,"abstract":"Magnetic topological insulators provide a platform for emergent phenomena arising from the interplay between magnetism and band topology. Here we report the single crystal growth, crystal structure, magnetic and transport properties, as well as the neutron scattering studies of topological insulator series <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mrow><mo>(</mo><msub><mi>Ge</mi><mrow><mn>1</mn><mo>−</mo><mi>δ</mi><mo>−</mo><mi>x</mi></mrow></msub><msub><mi>Mn</mi><mi>x</mi></msub><mo>)</mo></mrow><mn>2</mn></msub><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>5</mn></msub></mrow></math> <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>(</mo><mi>x</mi><mo>≤</mo><mn>0.47</mn></mrow><mo>,</mo><mo> </mo><mrow><mn>0.11</mn><mo>≤</mo><mi>δ</mi><mo>≤</mo><mn>0.20</mn><mo>)</mo></mrow></math>. Upon doping up to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>x</mi><mo>=</mo><mn>0.47</mn></mrow></math>, the lattice parameter <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>c</mi></math> decreases by 0.8%, while the lattice parameter <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>a</mi></math> remains nearly unchanged. Significant Ge vacancies and Ge/Bi site mixing are revealed via elemental analysis as well as refinements of the neutron and x-ray diffraction data, resulting in holes dominating the charge transport. At <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>x</mi><mo>=</mo><mn>0.47</mn></mrow></math>, below 10.8 K, a bilayer A-type antiferromagnetic ordered state emerges, featuring an ordered moment of 3.0(3) <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>μ</mi><mi>B</mi></msub><mo>/</mo><mi>Mn</mi></mrow></math> at 5 K, with the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>c</mi></math> axis as the easy axis. Magnetization data unveils a much stronger effective interlayer antiferromagnetic exchange interaction and a much smaller uniaxial anisotropy compared to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>MnBi</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>4</mn></msub></mrow></math>. We attribute the former to the shorter nearest-neighbor Mn-Mn interlayer superexchange path and the latter to the smaller ligand-field splitting in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mrow><mo>(</mo><msub><mi>Ge</mi><mrow><mn>1</mn><mo>−</mo><mi>δ</mi><mo>−</mo><mi>x</mi></mrow></msub><msub><mi>Mn</mi><mi>x</mi></msub><mo>)</mo></mrow><mn>2</mn></msub><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>5</mn></msub></mrow></math>. Our study demonstrates that this series of materials holds promise for the investigation of the layer Hall effect and quantum metric nonlinear Hall effect.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"68 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206133","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":"Augmented chalcopyrites: A search for new Cu-In-Te phases","authors":"Andy Paul Chen, Wei Nong, Maung Thway, Jose Recatala-Gomez, Haiwen Dai, Wenhao Zhai, D. V. Maheswar Repaka, Kedar Hippalgaonkar","doi":"10.1103/physrevmaterials.8.083801","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.083801","url":null,"abstract":"Chalcopyrites are ternary crystalline compounds which have found use in a diverse array of applications, from solar cells to thermoelectric devices. These are known to be ternary-compound analogs to diamond or sphalerite. “Defect chalcopyrites,” which are chalcopyrite structures stabilized with ordered vacancies and substitutions, are well attested and can serve as a method of tuning material properties through control of stoichiometry. In particular, defect chalcopyrites related to the thermoelectric compound <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CuInTe</mi><mn>2</mn></msub></math> comprise a large range of compositions in the pseudobinary system <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mrow><mo>(</mo><msub><mi>Cu</mi><mn>2</mn></msub><mi>Te</mi><mo>)</mo></mrow><mi>x</mi></msub><msub><mrow><mo>(</mo><msub><mi>In</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>3</mn></msub><mo>)</mo></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></mrow></math>, where <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>x</mi><mo>&lt;</mo><mn>0.5</mn></mrow></math>. In contrast, the converse case of “augmented chalcopyrites,” namely, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>x</mi><mo>&gt;</mo><mn>0.5</mn></mrow></math>, is much less known or studied. We report the discovery of a range of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Cu</mi><mn>2</mn></msub><mi>Te</mi></mrow></math>-rich compositions in this binary system where stable phases can potentially be found. Here, the stoichometry of augmented chalcopyrites is likely to be modulated by the concentration of defect clusters <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mrow><mo>[</mo><msubsup><mrow><mi>Cu</mi></mrow><mtext>In</mtext><mrow><mn>2</mn><mo>−</mo></mrow></msubsup><mo>·</mo><mn>2</mn><msubsup><mi>Cu</mi><mi>i</mi><mo>+</mo></msubsup><mo>]</mo></mrow><mn>0</mn></msup></math> in chalcopyrite <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CuInTe</mi><mn>2</mn></msub></math>.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"45 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206130","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":"No extraordinary χ(3) in lead-halide perovskites: placing an upper bound on Kerr nonlinearity by means of time-resolved interferometry","authors":"Dusan Lorenc, Ayan Zhumekenov, Osman M. Bakr, Zhanybek Alpichshev","doi":"10.1103/physrevmaterials.8.085403","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085403","url":null,"abstract":"Lead halide perovskites have recently been reported to demonstrate an exceptionally high nonlinear (Kerr) refractive index <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi mathvariant=\"normal\">n</mi><mn>2</mn></msub></math> of up to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mn>10</mn><mrow><mo>−</mo><mn>8</mn></mrow></msup><mspace width=\"4pt\"></mspace><msup><mrow><mi>cm</mi></mrow><mn>2</mn></msup><mo>/</mo><mi mathvariant=\"normal\">W</mi></mrow></math> in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>CH</mi><mn>3</mn></msub><msub><mi>NH</mi><mn>3</mn></msub><msub><mi>PbBr</mi><mn>3</mn></msub></mrow></math>. Other researchers, however, observe different, substantially more conservative numbers. In order to resolve this disagreement, the nonlinear Kerr index of a bulk sample of lead halide perovskite was measured directly by means of an interferometer. This approach has many advantages as compared to the more standard z-scan technique. In particular, this method allows studying the induced changes to the refractive index in a time-resolved manner, thus enabling to separate the different contributions to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>n</mi><mn>2</mn></msub></math>. The extracted <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi mathvariant=\"italic\">n</mi><mn>2</mn></msub></math> values for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CsPbBr</mi><mn>3</mn></msub></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MAPbBr</mi><mn>3</mn></msub></math> at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>λ</mi><mo>≈</mo><mn>1</mn><mspace width=\"0.16em\"></mspace><mi>µ</mi><mi mathvariant=\"normal\">m</mi></mrow></math> are <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>n</mi><mn>2</mn></msub><mo>=</mo><mo>+</mo><mn>2.1</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>14</mn></mrow></msup><mspace width=\"4pt\"></mspace><msup><mrow><mi>cm</mi></mrow><mn>2</mn></msup><mo>/</mo><mi mathvariant=\"normal\">W</mi></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>n</mi><mn>2</mn></msub><mo>=</mo><mo>+</mo><mn>6</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>15</mn></mrow></msup><mspace width=\"4pt\"></mspace><msup><mrow><mi>cm</mi></mrow><mn>2</mn></msup><mo>/</mo><mi mathvariant=\"normal\">W</mi></mrow></math>, respectively. Hence, these values are substantially lower than what has been indicated in most of the previous reports, implying the latter one should be regarded with great care.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"66 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206138","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":"Crystal growth and evolution of magnetism in the EuCuP-EuCuAs solid solution","authors":"Andrew F. May, Eleanor M. Clements, Xiaoping Wang, Heda Zhang, Brenden R. Ortiz","doi":"10.1103/physrevmaterials.8.084410","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084410","url":null,"abstract":"The hexagonal &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mi&gt;Eu&lt;/mi&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt; &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mi&gt;Cu&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mi&gt;Ag&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mi&gt;Au&lt;/mi&gt;&lt;mo&gt;;&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mi mathvariant=\"normal\"&gt;P&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mi&gt;As&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mi&gt;Sb&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mi&gt;Bi&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt; compounds host interesting electronic and magnetic properties, with seemingly intertwined topology and transport properties. One key feature of such behavior is the nature of the ordered magnetic structure. In EuCuAs, a topological Hall effect is caused by a conical spin structure that emerges when a field is applied within the easy-plane &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/math&gt; &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mo&gt;⊥&lt;/mo&gt;&lt;/math&gt; &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt; of the helical ground state that exists below the Neel temperature of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;mspace width=\"0.16em\"&gt;&lt;/mspace&gt;&lt;mi mathvariant=\"normal\"&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;. On the other hand, EuCuP is an easy-axis ferromagnet with a 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; near 31 K. Here, we investigate the evolution of the magnetic properties in &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;EuCuAs&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant=\"normal\"&gt;P&lt;/mi&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt; single crystals with &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;0.16&lt;/mn&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mn&gt;0.75&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;. Crystals grown by cooling slowly in a Sn flux possessed macroscale inhomogeneity of As/P, particularly for arsenic-rich crystals. However, growth in a Sn flux via an isothermal dwell at &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;600&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; produced crystals that were homogeneous within the resolution of the probes utilized to investigate these crystals. The unit cell volumes, Curie-Weiss temperatures, and magnetic transitions trend linearly with composition and the magnetic anisotropy is reduced in the alloys. The magnetization data of crystals with &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0.16&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt; and 0.24 indicate an easy-plane antiferromagnetic ground state while behavior similar to ferromagnetism is observed for crystals with &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mspace width=\"4pt\"&gt;&lt;/mspace&gt;&lt;mo&gt;≥&lt;/mo&gt;&lt;mo&gt; &lt;/mo&gt;&lt;mn&gt;0.41&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;. The temperature-dependent magnetization data possess multiple","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"36 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206134","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":"Low-intensity illumination induced relaxation and charge transport behavior of single crystal halide perovskites","authors":"Avisek Maity, Sudipta Chatterjee, Barnali Ghosh, A. K. Raychaudhuri","doi":"10.1103/physrevmaterials.8.085404","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085404","url":null,"abstract":"We have investigated impedance, electric modulus, and dielectric spectroscopies, along with AC conductivity, on single crystals of methylammonium lead iodide (MAPI) and formamidinium lead iodide (FAPI) in the frequency range <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>50</mn><mspace width=\"0.16em\"></mspace><mi>Hz</mi><mo>≤</mo><mi>f</mi><mo>≤</mo><mn>1</mn><mspace width=\"0.16em\"></mspace><mi>MHz</mi></mrow></math> in the dark and under low-intensity illumination (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>≤</mo><mn>80</mn><mspace width=\"0.28em\"></mspace><mo>µ</mo><mi mathvariant=\"normal\">W</mi><mo>/</mo><msup><mrow><mi>cm</mi></mrow><mn>2</mn></msup></mrow></math>). It is demonstrated that the relaxation observed in this frequency range in these single crystals can be attributed to space charge effects in the bulk of the crystals, which are caused by the finite time scale associated with charge relaxation, which can occur in this frequency range due to the large static dielectric constant and low conductivity of these solids. The relaxation was found to be faster in FAPI (with higher conductivity) compared to that in MAPI (with lower conductivity). The electron-hole pair generated by illumination enhances electronic conductivity and accelerates ionic migration by lowering the barrier; this, in turn, decreases the charge relaxation time and enhances the relaxation process. The barrier lowering inferred from the reduction in relaxation times by illumination is proposed to be associated with changes in the chemical potential attributed to carrier generation.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"406 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206132","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":"Vortex penetration along twin boundaries in pristine and proton-irradiated FeSe","authors":"Tong Ren, Yue Sun, Francesco Laviano, Ryousuke Sakagami, Zhi Xiang Shi, Tsuyoshi Tamegai","doi":"10.1103/physrevmaterials.8.084806","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084806","url":null,"abstract":"Below <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>T</mi><mi mathvariant=\"normal\">s</mi></msub><mo>∼</mo><mn>90</mn><mspace width=\"0.28em\"></mspace><mi mathvariant=\"normal\">K</mi></mrow></math>, single-crystal FeSe undergoes a structural phase transition coinciding with the emergence of lattice domain boundaries, termed twin boundaries. Polarized-light microscopy validated the presence of twin boundaries in pristine FeSe and indicated the existence of extensive microsized twining in proton-irradiated FeSe. In twinned FeSe, vortex penetration displays a fractal, mazelike pattern, likely guided by these twin domains. We speculate substantial microtwinning in the proton-irradiation crystals, yet macroscopic twin boundaries persist as primary conduits for vortex motion.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"180 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206136","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":"Differing vibrational properties of halide and chalcogenide perovskite semiconductors and impact on optoelectronic performance","authors":"Kevin Ye, Matan Menahem, Tommaso Salzillo, Florian Knoop, Boyang Zhao, Shanyuan Niu, Olle Hellman, Jayakanth Ravichandran, R. Jaramillo, Omer Yaffe","doi":"10.1103/physrevmaterials.8.085402","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085402","url":null,"abstract":"We report a comparative study of temperature-dependent photoluminescence and structural dynamics of two perovskite semiconductors, the chalcogenide <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>BaZrS</mi><mn>3</mn></msub></math> and the halide <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Cs</mi><mi>Pb</mi><msub><mi>Br</mi><mn>3</mn></msub></mrow></math>. These materials have similar crystal structures and direct band gaps, but we find that they have quite distinct optoelectronic and vibrational properties. Both materials exhibit thermally activated nonradiative recombination, but the nonradiative recombination rate in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>BaZrS</mi><mn>3</mn></msub></math> is four orders of magnitude faster than in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Cs</mi><mi>Pb</mi><msub><mi>Br</mi><mn>3</mn></msub></mrow></math>, for the crystals studied here. Raman spectroscopy reveals that the effects of phonon anharmonicity are far more pronounced in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Cs</mi><mi>Pb</mi><msub><mi>Br</mi><mn>3</mn></msub></mrow></math> than in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>BaZrS</mi><mn>3</mn></msub></math>. Further, although both materials feature a large dielectric response due to low-energy polar optical phonons, the phonons in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Cs</mi><mi>Pb</mi><msub><mi>Br</mi><mn>3</mn></msub></mrow></math> are substantially lower in energy than in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>BaZrS</mi><mn>3</mn></msub></math>. Our results suggest that electron-phonon coupling in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>BaZrS</mi><mn>3</mn></msub></math> is more effective at nonradiative recombination than in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Cs</mi><mi>Pb</mi><msub><mi>Br</mi><mn>3</mn></msub></mrow></math> and that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>BaZrS</mi><mn>3</mn></msub></math> may also have a substantially higher concentration of nonradiative recombination centers than <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Cs</mi><mi>Pb</mi><msub><mi>Br</mi><mn>3</mn></msub></mrow></math>. The low defect concentration in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Cs</mi><mi>Pb</mi><msub><mi>Br</mi><mn>3</mn></msub></mrow></math> may be related to the ease of lattice reconfiguration, typified by anharmonic bonding. It remains to be seen to what extent these differences are inherent to the chalcogenide and halide perovskites and to what extent they can be affected by materials processing.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":"57 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206135","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}