Neutron diffraction and observation of superconductivity for tungsten borides, WB and W2B4

Kayhan, Mehmet; Hildebrandt, Erwin; Frotscher, Michael; Senyshyn, Anatoliy; Hofmann, Kathrin; Alff, Lambert; Albert, Barbara

doi:10.1016/j.solidstatesciences.2012.05.036

Cited by 44 publications

(33 citation statements)

References 10 publications

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“…Borides with ordinary chains of boron atoms: (top) crystal structure of CrB (ICSD 44249, TaB (ortho) structure), [162] (middle) crystal structure of MnB (ICSD 76630, FeB (ortho) structure), [6] and (bottom) crystal structure of α-WB (ICSD 424240, MoB (tet) structure). [294] Boron atoms are in gray, metal atoms are in magenta.…”

Section: Adv Mater 2017 1604506mentioning

confidence: 99%

Rediscovering the Crystal Chemistry of Borides

2017

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For decades, borides have been primarily studied as crystallographic oddities. With such a wide variety of structures (a quick survey of the Inorganic Crystal Structure Database counts 1253 entries for binary boron compounds!), it is surprising that the applications of borides have been quite limited despite a great deal of fundamental research. If anything, the rich crystal chemistry found in borides could well provide the right tool for almost any application. The interplay between metals and the boron results in even more varied material's properties, many of which can be tuned via chemistry. Thus, the aim of this review is to reintroduce to the scientific community the developments in boride crystal chemistry over the past 60 years. We tie structures to material properties, and furthermore, elaborate on convenient synthetic routes toward preparing borides.

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Section: Adv Mater 2017 1604506mentioning

confidence: 99%

Rediscovering the Crystal Chemistry of Borides

2017

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“…For example, at least five different binary compounds formed between tungsten and boron have been reported: W 2 B, WB (two crystal structures), WB 2 , W 2 B 4 (formerly described as W 2 B 5 ), and WB 4 [1][2][3][4]. Metal borides also exhibit a range of interesting physical properties, including superconductivity [5] and superhardness [6].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of aluminum diboride products using 27Al, 11B NMR and ab initio studies

Turner

Koumoulis

et al. 2017

J Mater Sci

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Understanding different bonding environments in various metal borides provides insight into their structures and physical properties. Polycrystalline aluminum diboride (AlB 2 ) samples have been synthesized and compared both with a commercial sample and with the literature. One issue that arose is the relative ease with which boron-rich and aluminum deficient phases of aluminum borides can be presented in AlB 2 . Here, we report 27 Al, 11 B nuclear magnetic resonance (NMR) spectroscopy and first-principles calculations on AlB 2 in order to shed light on these different bonding environments at the atomic level and compare the structural and electronic properties of the products of different preparations. Along with the aforementioned, the present study also takes an indepth look at the nature of the 11 B and 27 Al nuclear spin-lattice relaxation recovery data for the AlB 2 and other superhard materials. The nuclear spinlattice relaxation has been measured for a static sample and with magic-angle spinning. The combination of NMR and band structure calculations highlights the synthetic challenges with superhard materials.

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“…This method, called “boron carbide synthesis,” proceeds at 1750–2000°C in a protective atmosphere or vacuum and is largely used in the industrial production of transition metal refractory borides . In this study, we adhere to the earlier established classical formula of the tungsten boride as “W 2 B 5 .” It was found that earlier proposed composition W 2 B 5 was actually the stoichiometric tungsten diboride W 2 B 4 crystallizing in a WB 2 ‐type structure . The “W 2 B 5 ” was found to be an intermediate compound from the process of WB 2 synthesis containing residual oxygen on the vacant B‐site …”

Section: Resultsmentioning

confidence: 91%

“…It was found that earlier proposed composition W 2 B 5 was actually the stoichiometric tungsten diboride W 2 B 4 crystallizing in a WB 2 -type structure. 46,47 The "W 2 B 5 " was found to be an intermediate compound from the process of WB 2 synthesis containing residual oxygen on the vacant B-site. 48 Figure 3 depicts the XPS data of B1s spectra of B 4 C and B 4 C-based materials densified in the presence of W 2 B 5 and WC by PECS at 1900°C.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Boron Carbide by Reactive‐Pulsed Electric Current Sintering in the Presence of Tungsten Boride

Radev

Avramova

Kovacheva

et al. 2016

Int J Applied Ceramic Tech

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The method of pulsed electric current sintering (PECS) has been used to obtain dense boron carbide (B4C) and B4C‐based composite materials containing tungsten boride (W2B5). To elucidate the role of the sintering additives and the mechanism of reactive densification, three types of materials have been obtained by PECS at 1850°C and 1900°C: “pure” B4C, B4C doped with 10 wt% W2B5, and B4C doped with 10 wt% tungsten carbide (WC). X‐ray diffraction and X‐ray photoelectron spectroscopy have been used to determine crystallite size, phase changes, and the peculiarities of the chemical bonds of the densified materials. Structural and mechanical properties of the materials have been investigated using scanning electron microscopy, optical microscopy, ultrasound velocity measurements, and hardness tests. The electrochemical impedance spectra have been used to investigate the electrical properties of the PECS‐ed materials.

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Neutron diffraction and observation of superconductivity for tungsten borides, WB and W2B4

Cited by 44 publications

References 10 publications

Rediscovering the Crystal Chemistry of Borides

Rediscovering the Crystal Chemistry of Borides

Synthesis and characterization of aluminum diboride products using 27Al, 11B NMR and ab initio studies

Synthesis of Boron Carbide by Reactive‐Pulsed Electric Current Sintering in the Presence of Tungsten Boride

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