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Paulsen C, Kösters J, Seidel S, Kuwata Y, Kotegawa H, Tou H, Sugawara H, Harima H, Pöttgen R. The orthorhombic-to-monoclinic phase transition in NbCrP – Peierls distortion of the chromium chain. Z KRIST-CRYST MATER 2021. [DOI: 10.1515/zkri-2021-2058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The equiatomic metal-rich phosphide NbCrP shows a structural phase transition around 125 K. The structures of the high- and low-temperature modifications were refined from single crystal X-ray diffractometer data of an un-twinned crystal: TiNiSi type, Pnma, a = 619.80(2), b = 353.74(4), c = 735.24(6) pm, wR = 0.0706, 288 F
2 values, 20 variables at 240 K and P121/c1, a = 630.59(3), b = 739.64(4), c = 933.09(5) pm, β = 132.491(6)°, wR = 0.0531, 1007 F
2 values, 57 variables at 90 K. The structural phase transition is of a classical Peierls type. The equidistant chromium chain in HT-NbCrP (353.7 pm Cr–Cr) splits pairwise into shorter (315.2 pm) and longer (373.2 pm) Cr–Cr distances. This goes along with a strengthening of Cr–P bonding. The superstructure formation is discussed on the basis of a group–subgroup scheme. Electronic structure calculations show a lifting of band degeneracy. Protection of the non-symmorphic symmetry of space group Pnma is crucial for the phase transition. The estimated charge modulation is consistent with the interpretation as Peierls transition.
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Affiliation(s)
- Christian Paulsen
- Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, 48149 Münster , Germany
| | - Jutta Kösters
- Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, 48149 Münster , Germany
| | - Stefan Seidel
- Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, 48149 Münster , Germany
| | - Yoshiki Kuwata
- Department of Physics , Kobe University , Kobe , Hyogo 657-8501 , Japan
| | - Hisashi Kotegawa
- Department of Physics , Kobe University , Kobe , Hyogo 657-8501 , Japan
| | - Hideki Tou
- Department of Physics , Kobe University , Kobe , Hyogo 657-8501 , Japan
| | - Hitoshi Sugawara
- Department of Physics , Kobe University , Kobe , Hyogo 657-8501 , Japan
| | - Hisatomo Harima
- Department of Physics , Kobe University , Kobe , Hyogo 657-8501 , Japan
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, 48149 Münster , Germany
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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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Zhou L, Yang L, Shao L, Chen B, Meng F, Qian Y, Xu L. General Fabrication of Boride, Carbide, and Nitride Nanocrystals via a Metal-Hydrolysis-Assisted Process. Inorg Chem 2017; 56:2440-2447. [PMID: 28218524 DOI: 10.1021/acs.inorgchem.6b02501] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metal boride, carbide, and nitride materials are useful owing to their wide variety of interesting chemical and physical properties. However, the synthesis of these materials with nano or mesoscale sizes is challenging due to the usually required high temperatures and long reaction durations. To our knowledge, the exploration of a number of simultaneous chemical reactions through rapid synthesis still remains a great challenge. In this study, a general route for the reduction and transformation of metal oxides into related metal boride (TiB2, MoB2, DyB4, ErB4, YB4, LaB6, CeB6, SmB6, EuB6), carbide (SiC, TiC, VC, WC, W2C, ZrC, MoC, NbC), and nitride (TiN, VN, BN, AlN, CrN, MgSiN2) nanocrystals were achieved at 150 °C. Here, the exothermic reaction of metal magnesium hydrolysis is utilized to assist the reaction in sealed stainless steel autoclaves. In situ temperature monitoring showed that the inside temperature increased quickly from 139 to 902 °C at the initial stage. The obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), and high-resolution TEM techniques. The low reaction temperature and cheap raw materials make it possible for large-scale synthesis of those nanomaterials.
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Affiliation(s)
- Ling Zhou
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University , Changsha, Hunan 410081, China
| | - Lishan Yang
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University , Changsha, Hunan 410081, China.,Changsha Research Institute of Mining and Metallurgy Co. Ltd. , Changsha 410012, China
| | - Li Shao
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University , Changsha, Hunan 410081, China
| | - Bo Chen
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, China
| | - Fanhui Meng
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, China
| | - Yitai Qian
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, China
| | - Liqiang Xu
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, China
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Mbarki M, Touzani RS, Rehorn CW, Gladisch FC, Fokwa BP. New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta2OsB2 and TaRuB. J SOLID STATE CHEM 2016. [DOI: 10.1016/j.jssc.2016.01.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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St. Touzani R, Mbarki M, Chen X, Fokwa BPT. Peierls‐Distorted Ru‐Chains and Boron Dumbbells in Nb
2
RuB
2
and Ta
2
RuB
2
from First‐Principles Calculations and Experiments. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rachid St. Touzani
- Institute of Inorganic ChemistryRWTH Aachen University52066AachenGermany
| | - Mohammed Mbarki
- Institute of Inorganic ChemistryRWTH Aachen University52066AachenGermany
| | - Ximeng Chen
- Institute of Inorganic ChemistryRWTH Aachen University52066AachenGermany
| | - Boniface P. T. Fokwa
- Institute of Inorganic ChemistryRWTH Aachen University52066AachenGermany
- Department of ChemistryUniversity of California Riverside (UCR)92521RiversideCAUSA
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Tian W, Chen H. Insight into the mechanical, thermodynamics and superconductor properties of NbRuB via first-principles calculation. Sci Rep 2016; 6:19055. [PMID: 26754861 PMCID: PMC4709565 DOI: 10.1038/srep19055] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/04/2015] [Indexed: 11/18/2022] Open
Abstract
Using the first-principles calculations, the electronic structure, chemical bonding, mechanical, thermodynamics and superconductor properties of NbRuB are investigated. The optimized lattice parameters were in good agreement with the experimental data. The analysis of the density of states and chemical bonding implies that the metallic behavior of NbRuB originates from the Ru and Nb, and the bonding behaviors are a mixture of covalent-ionic bonds. The bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and hardness of NbRuB were calculated. The results reveal that the NbRuB is ductility and the Vickers hardness is 15.06 GPa. Moreover, the 3D dependences of reciprocals of Young’s modulus is also calculated and discussed, showing strong anisotropic character for NbRuB. Finally, the Debye temperature and superconducting transition temperature are obtained.
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Affiliation(s)
- Wenyan Tian
- College of Electronics and Information Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China
| | - Haichuan Chen
- College of Electrical Engineering and Information Technology, Xihua University, Chengdu 610039, PR China
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Mbarki M, St. Touzani R, Fokwa BPT. Unexpected Synergy between Magnetic Iron Chains and Stacked B6Rings in Nb6Fe1−xIr6+xB8. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406397] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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Mbarki M, St. Touzani R, Fokwa BPT. Unexpected Synergy between Magnetic Iron Chains and Stacked B6Rings in Nb6Fe1−xIr6+xB8. Angew Chem Int Ed Engl 2014; 53:13174-7. [DOI: 10.1002/anie.201406397] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Indexed: 11/10/2022]
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Mbarki M, Touzani RS, Fokwa BPT. Experimental and Theoretical Investigations of the Ternary Boride NbRuB with a Layerlike Structure Type. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201301488] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Mohammed Mbarki
- Institute of Inorganic Chemistry, RWTH Aachen University, 52056 Aachen, Germany, http://www.ssc.rwth‐aachen.de/fokwa
| | - Rachid St. Touzani
- Institute of Inorganic Chemistry, RWTH Aachen University, 52056 Aachen, Germany, http://www.ssc.rwth‐aachen.de/fokwa
| | - Boniface P. T. Fokwa
- Institute of Inorganic Chemistry, RWTH Aachen University, 52056 Aachen, Germany, http://www.ssc.rwth‐aachen.de/fokwa
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