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Scheifers JP, Küpers M, Bakshi NG, Touzani RS, Gladisch FC, Rodewald UC, Pöttgen R, Fokwa BPT. Fe- and B-Chains in the Ti 5-xFe 1-yOs 6+x+yB 6 Structure Type Derived from Chemical Twinning of the Nb 1-xOs 1+xB Type: Experimental and Computational Investigations. Inorg Chem 2023. [PMID: 37220306 DOI: 10.1021/acs.inorgchem.3c00837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The complex metal-rich boride Ti5-xFe1-yOs6+x+yB6 (0 < x,y < 1), crystallizing in a new structure type (space group Cmcm, no. 63), was prepared by arc-melting. The new structure contains both isolated boron atoms and zigzag boron chains (B-B distance of 1.74 Å), a rare combination among metal-rich borides. In addition, the structure also contains Fe-chains running parallel to the B-chains. Unlike in previously reported structures, these Fe-chains are offset from each other and arranged in a triangular manner with intrachain and interchain distances of 2.98 and 6.69 Å, respectively. Density functional theory (DFT) calculations predict preferred ferromagnetic interactions within each chain but only small energy differences for different magnetic interactions between them, suggesting a potentially weak long-range order. This new structure offers the opportunity to study new configurations and interactions of magnetic elements for the design of magnetic materials.
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Affiliation(s)
- Jan P Scheifers
- Department of Chemistry, University of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Michael Küpers
- Institut für Anorganische Chemie, RWTH Aachen University, Melatener Straße 2, 52074 Aachen, Germany
| | - Nika G Bakshi
- Department of Chemistry, University of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Rashid St Touzani
- Institut für Anorganische Chemie, RWTH Aachen University, Melatener Straße 2, 52074 Aachen, Germany
| | - Fabian C Gladisch
- Institut für Anorganische Chemie, RWTH Aachen University, Melatener Straße 2, 52074 Aachen, Germany
| | - Ute Ch Rodewald
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany
| | - Boniface P T Fokwa
- Department of Chemistry, University of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
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Scheifers JP, Flores JH, Janka O, Pöttgen R, Fokwa BPT. Triangular Arrangement of Ferromagnetic Iron Chains in the High‐
T
C
Ferromagnet TiFe
1−x
Os
2+x
B
2. Chemistry 2022; 28:e202201058. [DOI: 10.1002/chem.202201058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Jan P. Scheifers
- Department of Chemistry University of California Riverside 900 University Avenue 92521 Riverside CA USA
| | - Justin H. Flores
- Bourns College of Engineering University of California Riverside 900 University Avenue 92521 Riverside CA USA
| | - Oliver Janka
- Anorganische Festkörperchemie Universität des Saarlandes Campus C 4 1 66123 Saarbrücken Germany
- Institut für Anorganische und Analytische Chemie Westfälische Wilhelms-Universität Münster Corrensstrasse 30 48149 Münster Germany
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie Westfälische Wilhelms-Universität Münster Corrensstrasse 30 48149 Münster Germany
| | - Boniface P. T. Fokwa
- Department of Chemistry University of California Riverside 900 University Avenue 92521 Riverside CA USA
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Experimental and computational investigations of TiIrB: a new ternary boride with Ti1+x
Rh2−x+y
Ir3−y
B3-type structure. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2021. [DOI: 10.1515/znb-2021-0121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A new ternary phase, TiIrB, was synthesized by arc-melting of the elements and characterized by powder X-ray diffraction. The compound crystallizes in the orthorhombic Ti1+x
Rh2−x+y
Ir3−y
B3 structure type, space group Pbam (no. 55) with the lattice parameters a = 8.655(2), b = 15.020(2), and c = 3.2271(4) Å. Density Functional Theory (DFT) calculations were carried out to understand the electronic structure, including a Bader charge analysis. The charge distribution of TiIrB in the Ti1+x
Rh2−x+y
Ir3−y
B3-type phase has been evaluated for the first time, and the results indicate that more electron density is transferred to the boron atoms in the zigzag B4 units than to isolated boron atoms.
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Iyer AK, Zhang Y, Scheifers JP, Fokwa BP. Structural variations, relationships and properties of M2B metal borides. J SOLID STATE CHEM 2019. [DOI: 10.1016/j.jssc.2018.12.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sharma N, Mbarki M, Zhang Y, Huq A, Fokwa BPT. Structural-Distortion-Driven Magnetic Transformation from Ferro- to Ferrimagnetic Iron Chains in B 6 -based Nb 6 FeIr 6 B 8. Angew Chem Int Ed Engl 2018; 57:10323-10327. [PMID: 29892987 DOI: 10.1002/anie.201804841] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Indexed: 11/09/2022]
Abstract
We report on a structural distortion of kinetically stable B6 -based ferromagnetic Nb6 FeIr6 B8 that induces an unprecedented transformation of a ferromagnetic Fe chain into two ferrimagnetic Fe chains through superstructure formation. Density functional theory calculations showed that the ferromagnetic Fe-Fe intrachain interactions found in the undistorted structure become ferrimagnetic in the distorted superstructure, mainly because the two independent iron atoms building each chain interact antiferromagnetically and carry different magnetic moments. High-temperature SQUID magnetometry confirmed ferrimagnetic ordering at 525 K with a high and negative Weiss constant of -972 K indicating the presence of strong antiferromagnetic interactions, as predicted. This finding paves the way for the development of low-dimensional magnetic intermetallic systems based on Heisenberg ferrimagnetic chains, which have previously been studied only in molecular-based compounds.
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Affiliation(s)
- Neetika Sharma
- Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA
| | - Mohammed Mbarki
- Institute of Inorganic Chemistry, RWTH Aachen University, 52074, Aachen, Germany
| | - Yuemei Zhang
- Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA
| | - Ashfia Huq
- Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Boniface P T Fokwa
- Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA
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Sharma N, Mbarki M, Zhang Y, Huq A, Fokwa BPT. Structural‐Distortion‐Driven Magnetic Transformation from Ferro‐ to Ferrimagnetic Iron Chains in B
6
‐based Nb
6
FeIr
6
B
8. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Neetika Sharma
- Department of Chemistry University of California, Riverside Riverside CA 92521 USA
| | - Mohammed Mbarki
- Institute of Inorganic Chemistry RWTH Aachen University 52074 Aachen Germany
| | - Yuemei Zhang
- Department of Chemistry University of California, Riverside Riverside CA 92521 USA
| | - Ashfia Huq
- Chemical and Engineering Materials Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Boniface P. T. Fokwa
- Department of Chemistry University of California, Riverside Riverside CA 92521 USA
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Scheifers JP, Zhang Y, Fokwa BPT. Boron: Enabling Exciting Metal-Rich Structures and Magnetic Properties. Acc Chem Res 2017; 50:2317-2325. [PMID: 28792209 DOI: 10.1021/acs.accounts.7b00268] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Boron's unique chemical properties and its reactions with metals have yielded the large class of metal borides with compositions ranging from the most boron-rich YB66 (used as monochromator for synchrotron radiation) up to the most metal-rich Nd2Fe14B (the best permanent magnet to date). The excellent magnetic properties of the latter compound originate from its unique crystal structure to which the presence of boron is essential. In general, knowing the crystal structure of any given extended solid is the prerequisite to understanding its physical properties and eventually predicting new synthetic targets with desirable properties. The ability of boron to form strong chemical bonds with itself and with metallic elements has enabled us to construct new structures with exciting properties. In recent years, we have discovered new boride structures containing some unprecedented boron fragments (trigonal planar B4 units, planar B6 rings) and low-dimensional substructures of magnetically active elements (ladders, scaffolds, chains of triangles). The new boride structures have led to new superconducting materials (e.g., NbRuB) and to new itinerant magnetic materials (e.g., Nb6Fe1-xIr6+xB8). The study of boride compounds containing chains (Fe-chains in antiferromagnetic Sc2FeRu5B2), ladders (Fe-ladders in ferromagnetic Ti9Fe2Rh18B8), and chains of triangles (Cr3 chains in ferrimagnetic and frustrated TiCrIr2B2) of magnetically active elements allowed us to gain a deep understanding of the factors (using density functional theory calculations) that can affect magnetic ordering of such low-dimensional magnetic units. We discovered that the magnetic properties of phases containing these magnetic subunits can be drastically tuned by chemical substitution within the metallic nonmagnetic network. For example, the small hysteresis (measure of magnetic energy storage) of Ti2FeRh5B2 can be successively increased up to 24-times by gradually substituting Ru for Rh, a result that was even surpassed (up to 54-times the initial value) for Ru/Ir substitutions. Also, the type of long-range magnetic interactions could be drastically tuned by appropriate substitutions in the metallic nonmagnetic network as demonstrated using both experimental and theoretical methods. It turned out that Ru-rich and valence electron poor metal borides adopting the Ti3Co5B2 or the Th7Fe3 structure types have dominating antiferromagnetic interactions, while in Rh-rich (or Ir-rich) and valence electron rich phases ferromagnetic interactions prevail, as found, for example, in the Sc2FeRu5-xRhxB2 and FeRh6-xRuxB3 series. Fascinatingly, boron clusters (e.g., B6 rings) even directly interact in some cases with the magnetic subunits, an interaction which was found to favor the Fe-Fe magnetic exchange interactions in the ferromagnetic Nb6Fe1-xIr6+xB8. Using less expensive transition metals, we have recently predicted new itinerant magnets, the experimental proof of which is still pending. Furthermore, new structures have been discovered, all of which are being studied experimentally and computationally with the aim of finding new superconductors, magnets, and mechanically hard materials. A new direction is being pursued in our group, as binary and ternary transition metal borides show great promise as efficient water splitting electrocatalysts at the micro- and nanoscale.
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Affiliation(s)
- Jan P. Scheifers
- Departments of Chemistry, University of California Riverside (UCR), Riverside, California 92521, United States
| | - Yuemei Zhang
- Departments of Chemistry, University of California Riverside (UCR), Riverside, California 92521, United States
| | - Boniface P. T. Fokwa
- Departments of Chemistry, University of California Riverside (UCR), Riverside, California 92521, United States
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Ha MA, Baxter ET, Cass AC, Anderson SL, Alexandrova AN. Boron Switch for Selectivity of Catalytic Dehydrogenation on Size-Selected Pt Clusters on Al2O3. J Am Chem Soc 2017; 139:11568-11575. [DOI: 10.1021/jacs.7b05894] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mai-Anh Ha
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Eric T. Baxter
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Ashley C. Cass
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Scott L. Anderson
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Anastassia N. Alexandrova
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
- California NanoSystems Institute, Los Angeles, California 90095, United States
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