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  • 1. Beställ onlineKöp publikationen >>
    Carlsson, Adam
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Explorations of boron-based materials through theoretical simulations2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis focuses on boron-based materials, notable for their structural complexity and unique combination of ceramic and metallic properties. These properties typically result in materials with high mechanical strength, electrical conductivity, and melting points. Among these materials are MAB phases, a family of layered materials comprised of a transition metal (M), an A-element (typically an element from Group 13-14), and boron (B). The layered nature of these materials provides a pathway towards the realization of 2D materials, coined MBenes (or boridene), through chemical exfoliation.

    While the potential for discovering novel materials is immense, their realization often demands extensive experimental efforts. Theoretical models may here be used as a filter by guiding experimental endeavours. The work presented herein aims to leverage theoretical models and to develop frameworks suitable for reliable thermodynamical predictions in hope of the discovery of additional boron-based materials.

    First-principles calculations, particularly density functional theory (DFT), have extensively been employed in this thesis to determine the ground state energy of materials and predict their stability or tendency to decompose. However, first-principles calculations typically rely on a pre-defined crystal structure which may be constructed through a priori information or obtained through the use of crystal structure prediction (CSP) frameworks. We herein explore both of these approaches by i) systematically substituting elements in known low-energy structures, and ii) deriving novel low-energy structures by combining CSP with cluster expansion (CE) models.

    The first approach is herein exemplified when considering the low-energy structures of V3B2 (P4/mbm) and Cr5B3 (I4/mbm). These structures are comprised of two M-sites in addition to boron and thus form the general compositions M’2M’’B2 and M’4M’’B3, respectively. In a follow-up project, this approach was refined by probing the Materials Project database for additional binary boron-based materials with structures of this nature. The M-sites of these candidate structures were further populated with elements ranging from Group 2 to 14 with the aim of discovering novel ternary boron-based materials.

    Alternatively, a hybrid method of the two techniques is herein explored in which manually designed hexagonal structures were made based on orthorhombic low-energy counterpart structures. A set of structural polymorphs for the M2AB2, M3AB4, M4AB6, MAB, and M4AB4 compositions were studied with varying stacking sequences followed by the evaluation of their thermodynamical stability.

    The second approach requires little to no structural information but is typically limited to considering fewer material systems due to a higher computational cost. This approach is herein applied to study low-energy basins within the complex phase space of (MoxSc1-x)2AlB2 and (M’xM’’1-x)3AlB4 systems with the aim of finding novel quaternary boron-based materials. A framework, suitable for exploring chemical phase spaces of complex systems, was herein developed by combining CSP and CE models with DFT calculations. The suggested framework is initiated by performing CSP simulations on the n-1 dimensional systems. Identified low-energy structures are subsequently used as input lattices to construct CE models for the n-dimensional system. The low-energy basins found in the n-dimensional system may potentially be used as seed structures in a comprehensive CSP simulation or as input structures for high-throughput screening. This approach, not only provides an efficient pathway to identify low-energy basins of complex material systems, but also attempts to bridge the gap in materials discovery with or without prerequisite information.

    The aspiration of bridging the gap between state-of-the-art simulation techniques, whether reliant on a priori information or not, is rooted in the intention of enhancing the foundation of materials discovery. The refinement of these theoretical simulations serves to guide and augment experimental efforts for the synthesis of novel materials which is pivotal for addressing and achieving current and future sustainability goals.

    Delarbeten
    1. Theoretical predictions of phase stability for orthorhombic and hexagonal ternary MAB phases
    Öppna denna publikation i ny flik eller fönster >>Theoretical predictions of phase stability for orthorhombic and hexagonal ternary MAB phases
    2022 (Engelska)Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 24, nr 18, s. 11249-11258Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In the quest for finding novel thermodynamically stable, layered, MAB phases promising for synthesis, we herein explore the phase stability of ternary MAB phases by considering both orthorhombic and hexagonal crystal symmetries for various compositions (MAB, M2AB2, M3AB4, M4AB4, and M4AB6 where M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, and Co, A = Al, Ga, and In, and B is boron). The thermodynamic stability of seven previously synthesized MAB phases is confirmed, three additional phases are predicted to be stable, and 23 phases are found to be close to stable. Furthermore, the crystal symmetry preference for forming orthorhombic or hexagonal crystal structures is investigated where the considered Al-based MAB phases tend to favour orthorhombic structures whereas Ga- and In-based phases in general prefer hexagonal structures. The theoretically predicted stable MAB phases along with the structural preference is intended to both guide experimental efforts and to give an insight into the stability for different crystal symmetries of MAB phases.

    Ort, förlag, år, upplaga, sidor
    Cambridge, United Kingdom: Royal Society of Chemistry, 2022
    Nationell ämneskategori
    Oorganisk kemi
    Identifikatorer
    urn:nbn:se:liu:diva-184837 (URN)10.1039/d1cp05750b (DOI)000788174800001 ()35481473 (PubMedID)
    Anmärkning

    Funding Agencies|Swedish Research Council, European Commission [2019-05047, 2018-05973]; Knut & Alice Wallenberg Foundation [KAW 2020.0033]

    Tillgänglig från: 2022-05-12 Skapad: 2022-05-12 Senast uppdaterad: 2024-02-02Bibliografiskt granskad
    2. Finding stable multi-component materials by combining cluster expansion and crystal structure predictions
    Öppna denna publikation i ny flik eller fönster >>Finding stable multi-component materials by combining cluster expansion and crystal structure predictions
    2023 (Engelska)Ingår i: npj Computational Materials, E-ISSN 2057-3960, Vol. 9, nr 1, artikel-id 21Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    A desired prerequisite when performing a quantum mechanical calculation is to have an initial idea of the atomic positions within an approximate crystal structure. The atomic positions combined should result in a system located in, or close to, an energy minimum. However, designing low-energy structures may be a challenging task when prior knowledge is scarce, specifically for large multi-component systems where the degrees of freedom are close to infinite. In this paper, we propose a method for identification of low-energy crystal structures within multi-component systems by combining cluster expansion and crystal structure predictions with density-functional theory calculations. Crystal structure prediction searches are applied to the Mo2AlB2 and Sc2AlB2 ternary systems to identify candidate structures, which are subsequently used to explore the quaternary (pseudo-binary) (MoxSc1-x)(2)AlB2 system through the cluster expansion formalism utilizing the ground-state search approach. Furthermore, we show that utilizing low-energy structures found within the cluster expansion ground-state search as seed structures within crystal structure predictions of (MoxSc1-x)(2)AlB2 can significantly reduce the computational demands. With this combined approach, we not only correctly identified the recently discovered Mo(4/3)Sc(2/3)AlB(2)i-MAB phase, comprised of in-plane chemical ordering of Mo and Sc and with Al in a Kagome lattice, but also predict additional low-energy structures at various concentrations. This result demonstrates that combining crystal structure prediction with cluster expansion provides a path for identifying low-energy crystal structures in multi-component systems by employing the strengths from both frameworks.

    Ort, förlag, år, upplaga, sidor
    NATURE PORTFOLIO, 2023
    Nationell ämneskategori
    Teoretisk kemi
    Identifikatorer
    urn:nbn:se:liu:diva-192169 (URN)10.1038/s41524-023-00971-3 (DOI)000929023800001 ()
    Anmärkning

    Funding Agencies|Linkoeping University

    Tillgänglig från: 2023-03-07 Skapad: 2023-03-07 Senast uppdaterad: 2024-02-02
    3. Synthesis, Characterization, and Modeling of a Chemically Ordered Quaternary Boride, Mo4MnSiB2
    Öppna denna publikation i ny flik eller fönster >>Synthesis, Characterization, and Modeling of a Chemically Ordered Quaternary Boride, Mo4MnSiB2
    Visa övriga...
    2023 (Engelska)Ingår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 23, nr 5, s. 3258-3263Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The recent discovery of chemical ordering in quaternary borides offers new ways of exploring properties and functionalities of these laminated phases. Here, we have synthesized and investigated chemical ordering of the laminated Mo4MnSiB2 (T2) phase, thereby introducing a magnetic element into the family of materials coined o-MAB phases. By X-ray diffraction and scanning transmission electron microscopy, we provide evidence for out-of-plane chemical ordering of Mo and Mn, with Mo occupying the 16l site and Mn preferentially residing in the 4c site. Mn and B constitute quasi-two-dimensional layers in the laminated material. We have therefore also studied the magnetic properties by magnetometry, and no sign of long-range magnetic order is observed. An initial assessment of the magnetic ordering has been further studied by density functional theory (DFT) calculations, and while we find an antiferromagnetic configuration to be the most stable one, ferromagnetic ordering is very close in energy.

    Ort, förlag, år, upplaga, sidor
    AMER CHEMICAL SOC, 2023
    Nationell ämneskategori
    Den kondenserade materiens fysik
    Identifikatorer
    urn:nbn:se:liu:diva-193401 (URN)10.1021/acs.cgd.2c01416 (DOI)000968059000001 ()
    Anmärkning

    Funding Agencies|Knut and Alice Wallenberg (KAW) Foundation [KAW 2020.0033]; Swedish Research Council [2019-04233, 2021-00471, 2018-05973]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoeping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; Deutsche Forschungsgemeinschaft (DFG) [CRC/TRR 270, 405553726]

    Tillgänglig från: 2023-05-03 Skapad: 2023-05-03 Senast uppdaterad: 2024-02-02
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  • 2.
    Carlsson, Adam
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Finding stable multi-component materials by combining cluster expansion and crystal structure predictions2023Ingår i: npj Computational Materials, E-ISSN 2057-3960, Vol. 9, nr 1, artikel-id 21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A desired prerequisite when performing a quantum mechanical calculation is to have an initial idea of the atomic positions within an approximate crystal structure. The atomic positions combined should result in a system located in, or close to, an energy minimum. However, designing low-energy structures may be a challenging task when prior knowledge is scarce, specifically for large multi-component systems where the degrees of freedom are close to infinite. In this paper, we propose a method for identification of low-energy crystal structures within multi-component systems by combining cluster expansion and crystal structure predictions with density-functional theory calculations. Crystal structure prediction searches are applied to the Mo2AlB2 and Sc2AlB2 ternary systems to identify candidate structures, which are subsequently used to explore the quaternary (pseudo-binary) (MoxSc1-x)(2)AlB2 system through the cluster expansion formalism utilizing the ground-state search approach. Furthermore, we show that utilizing low-energy structures found within the cluster expansion ground-state search as seed structures within crystal structure predictions of (MoxSc1-x)(2)AlB2 can significantly reduce the computational demands. With this combined approach, we not only correctly identified the recently discovered Mo(4/3)Sc(2/3)AlB(2)i-MAB phase, comprised of in-plane chemical ordering of Mo and Sc and with Al in a Kagome lattice, but also predict additional low-energy structures at various concentrations. This result demonstrates that combining crystal structure prediction with cluster expansion provides a path for identifying low-energy crystal structures in multi-component systems by employing the strengths from both frameworks.

    Ladda ner fulltext (pdf)
    fulltext
  • 3.
    Tao, Quanzheng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Halim, Joseph
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Palisaitis, Justinas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Carlsson, Adam
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Wiedwald, Ulf
    Univ Duisburg Essen, Germany.
    Farle, Michael
    Univ Duisburg Essen, Germany.
    Persson, Per O A
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Synthesis, Characterization, and Modeling of a Chemically Ordered Quaternary Boride, Mo4MnSiB22023Ingår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 23, nr 5, s. 3258-3263Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The recent discovery of chemical ordering in quaternary borides offers new ways of exploring properties and functionalities of these laminated phases. Here, we have synthesized and investigated chemical ordering of the laminated Mo4MnSiB2 (T2) phase, thereby introducing a magnetic element into the family of materials coined o-MAB phases. By X-ray diffraction and scanning transmission electron microscopy, we provide evidence for out-of-plane chemical ordering of Mo and Mn, with Mo occupying the 16l site and Mn preferentially residing in the 4c site. Mn and B constitute quasi-two-dimensional layers in the laminated material. We have therefore also studied the magnetic properties by magnetometry, and no sign of long-range magnetic order is observed. An initial assessment of the magnetic ordering has been further studied by density functional theory (DFT) calculations, and while we find an antiferromagnetic configuration to be the most stable one, ferromagnetic ordering is very close in energy.

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  • 4. Beställ onlineKöp publikationen >>
    Carlsson, Adam
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Computational prediction of novel MAB phases2022Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The synthesis procedure of any materials system is often considered a challenging task if performed without any prior knowledge. Theoretical models may thus be used as an external input and guide experimental efforts toward novel exotic materials which are most likely to be synthesizable. The aim of this work is to apply theoretical models and develop frameworks for reliable predictions of thermodynamically stable materials. The material in focus herein is the family of atomic layered boride-based materials referred to as MAB phases.

    The ground state energy of a material system may be obtained by applying firstprincipal calculations, such as density functional theory (DFT), which has thoroughly been used throughout this thesis. However, performing modern state-of-the-art quantum mechanical calculations, in general, relies on a pre-defined crystal structure which may be constructed based on an a priori known structure or obtained through the use of crystal structure prediction models. In this work, both approaches are explored. We herein perform a thermodynamical screening study to predict novel stable ternary boron-based materials by considering M2AB2, M3AB4, M4AB6, MAB and M4AB4 compositions in orthorhombic and hexagonal symmetries with inspiration from experimentally synthesized MAB phases. The considered atomic elements are M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, A = Al, Ga, In, and B is boron. Among the considered compounds, seven experimentally synthesized phases are verified as stable, and we predict the three hypothetical phases to be stable - Hf2InB2, Zr2InB2, and Mo4AlB4. Additionally, 23 phases of varying symmetries and compositions are predicted as close to stable or to be metastable.

    However, the assumption of assigning initial crystal structures based on neighbouring compounds may drastically limit the outcome of a screening study. State-of-the-art techniques to generate low energy crystal structures within the considered material phase space is thus explored. More specifically, the Mo-Sc-Al-B system is studied along the ternary joints of (MoxSc1-x)2AlB2 where 0 < x < 1 by using the cluster expansion (CE) and the crystal structure prediction (CSP) codes, CLEASE and USPEX, in analogy. Previous attempts to study the Mo-Sc-Al-B system has been limited by only considering either hexagonal or orthorhombic symmetries. We challenge such approaches by covering larger portions of the phase space efficiently by combining CSP and CE frameworks. The Mo4/3Sc2/3AlB2 (R ̅3m) phase, previously referred to as i-MAB, is verified stable in addition to Mo2/3Sc4/3AlB2 (R3).

    The suggested approach of combining CE and CSP frameworks for investigating multi-component systems consists of initially performing CSP searches on the systems of smaller order constituting the system in focus. In the pseudo-ternary (MoxSc1-x)2AlB2 system, this refers to performing CSP searches on the ternary Mo2AlB2 and Sc2AlB2 systems. In addition, we also consider the structures of experimentally known phases with similar compositions. The complete set of structures obtained either from CSP or public databases, was later used to design CE models where mixing tendencies in addition to stability determined which model to further study. The predicted low-energy structures of the CE model were relaxed and used as seed structures within a complete CSP search covering the (MoxSc1-x)2AlB2 system for 0 < x < 1. We demonstrate that the use of seed structures, obtained from CE models, efficiently improved the search for low-energy structures within a multi-component system. The suggested approach is yet to be tested on any other system but is applicable to any alternative multi-component system.

    Delarbeten
    1. Theoretical predictions of phase stability for orthorhombic and hexagonal ternary MAB phases
    Öppna denna publikation i ny flik eller fönster >>Theoretical predictions of phase stability for orthorhombic and hexagonal ternary MAB phases
    2022 (Engelska)Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 24, nr 18, s. 11249-11258Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In the quest for finding novel thermodynamically stable, layered, MAB phases promising for synthesis, we herein explore the phase stability of ternary MAB phases by considering both orthorhombic and hexagonal crystal symmetries for various compositions (MAB, M2AB2, M3AB4, M4AB4, and M4AB6 where M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, and Co, A = Al, Ga, and In, and B is boron). The thermodynamic stability of seven previously synthesized MAB phases is confirmed, three additional phases are predicted to be stable, and 23 phases are found to be close to stable. Furthermore, the crystal symmetry preference for forming orthorhombic or hexagonal crystal structures is investigated where the considered Al-based MAB phases tend to favour orthorhombic structures whereas Ga- and In-based phases in general prefer hexagonal structures. The theoretically predicted stable MAB phases along with the structural preference is intended to both guide experimental efforts and to give an insight into the stability for different crystal symmetries of MAB phases.

    Ort, förlag, år, upplaga, sidor
    Cambridge, United Kingdom: Royal Society of Chemistry, 2022
    Nationell ämneskategori
    Oorganisk kemi
    Identifikatorer
    urn:nbn:se:liu:diva-184837 (URN)10.1039/d1cp05750b (DOI)000788174800001 ()35481473 (PubMedID)
    Anmärkning

    Funding Agencies|Swedish Research Council, European Commission [2019-05047, 2018-05973]; Knut & Alice Wallenberg Foundation [KAW 2020.0033]

    Tillgänglig från: 2022-05-12 Skapad: 2022-05-12 Senast uppdaterad: 2024-02-02Bibliografiskt granskad
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  • 5.
    Carlsson, Adam
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Theoretical predictions of phase stability for orthorhombic and hexagonal ternary MAB phases2022Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 24, nr 18, s. 11249-11258Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the quest for finding novel thermodynamically stable, layered, MAB phases promising for synthesis, we herein explore the phase stability of ternary MAB phases by considering both orthorhombic and hexagonal crystal symmetries for various compositions (MAB, M2AB2, M3AB4, M4AB4, and M4AB6 where M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, and Co, A = Al, Ga, and In, and B is boron). The thermodynamic stability of seven previously synthesized MAB phases is confirmed, three additional phases are predicted to be stable, and 23 phases are found to be close to stable. Furthermore, the crystal symmetry preference for forming orthorhombic or hexagonal crystal structures is investigated where the considered Al-based MAB phases tend to favour orthorhombic structures whereas Ga- and In-based phases in general prefer hexagonal structures. The theoretically predicted stable MAB phases along with the structural preference is intended to both guide experimental efforts and to give an insight into the stability for different crystal symmetries of MAB phases.

    Ladda ner fulltext (pdf)
    fulltext
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