Spatial distribution of electrons near the Fermi level in the metallic LaB6 through accurate X-ray charge density study

Kasai, Hidetaka; Nishibori, Eiji

doi:10.1038/srep41375

Cited by 17 publications

(10 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies of the Fermi level may help provide insight into the movement of electrons within the system. The spatial distribution of electrons near the Fermi level was recently reported for trivalent LaB 6 and divalent BaB 6 [67], and weak electron lobes were found around the interior-B 6 octahedral bond (Figure 4A). Comparing theoretical and experimental work, it was determined that these electron lobes were responsible for the conductive π-electrons in LaB 6 .…”

Section: Controlling the Plasmon Of Lab6supporting

confidence: 70%

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

Mattox

2018

Materials

View full text Add to dashboard Cite

While traditional noble metal (Ag, Au, and Cu) nanoparticles are well known for their plasmonic properties, they typically only absorb in the ultraviolet and visible regions. The study of metal hexaborides, lanthanum hexaboride (LaB6) in particular, expands the available absorbance range of these metals well into the near-infrared. As a result, LaB6 has become a material of interest for its energy and heat absorption properties, most notably to those trying to absorb solar heat. Given the growing popularity of LaB6, this review focuses on the advances made in the past decade with respect to controlling the plasmonic properties of LaB6 nanoparticles. This review discusses the fundamental structure of LaB6 and explains how decreasing the nanoparticle size changes the atomic vibrations on the surface and thus the plasmonic absorbance band. We explain how doping LaB6 nanoparticles with lanthanide metals (Y, Sm, and Eu) red-shifts the absorbance band and describe research focusing on the correlation between size dependent and morphological effects on the surface plasmon resonance. This work also describes successes that have been made in dispersing LaB6 nanoparticles for various optical applications, highlighting the most difficult challenges encountered in this field of study.

show abstract

Section: Controlling the Plasmon Of Lab6supporting

confidence: 70%

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

Mattox

2018

Materials

View full text Add to dashboard Cite

show abstract

“…The low shear deformation resistance associated with the {110}< 111> can be explained by the weak B3‐B3 and B2‐B3 bonds within the B 6 octahedron, which are formed by overlapping of perpendicular B 2 p orbitals (called τ bond). The weak τ bond was proposed by Zhou et al through the electronic structure investigation of YB 6 and related materials and was experimentally proven in LaB 6 by Kasai et al using accurate X‐ray charge density study. The weak intra‐octahedral B‐B bond is responsible for the low shear deformation resistance associated with the {110}< 111> .…”

Section: Discussionmentioning

confidence: 92%

Y₅Si₂B₈: A theoretically predicted new damage‐tolerant MAB phase with layered crystal structure

et al. 2018

View full text Add to dashboard Cite

Layer structured MAB phases (M=transition metal, A=IIIA or IVA group element, B is boron) are promising ternary borides for high and ultrahigh‐temperature applications. Herein, a new MAB phase Y5Si2B8 consisting of alternative stacking of YB4 and Y3Si2 slabs along the [001] direction is investigated. Density functional theory (DFT) calculations on the electronic structure and chemical bonding reveal that this new MAB phase has diverse chemical bonding and properties similar to MAX phases. The strong covalent bonds in the two‐dimensional B network on (001) plane in the YB4 slab and between Si atoms on (002) plane in the Y3Si2‐slab warrant the high stiffness (Ex=288 GPa) of Y5Si2B8 in the ab plane and the weak Y2‐Si and Y1‐B2 bonds that connecting the YB4 and Y3Si2 slabs underpin the low Young's modulus in [001] direction (Ez=200 GPa). The low shear deformation resistance is due to the presence of the metallic bond and the weak bond within the B6 octahedral. The possible slip systems are {001}< 100> and {110}< 111> . Based on the low shear modulus (G = 104 GPa) and Pugh's ratio G/B, Y5Si2B8 is predicted as a damage tolerant MAB phase. Y5Si2B8 is also predicted electrically conductive and the conductivity is higher in directions parallel to ab plane. In addition, temperature‐dependent phonon and electron heat capacity are predicted based on the electron and phonon density of states analysis.

show abstract

“…The powder profiles were analyzed by the combination of Rietveld refinement and multipole refinement. The details of analysis were described in elsewhere 12 . The observed structure factors were extracted from 30 K data.…”

Section: Resultsmentioning

confidence: 99%

“…The diffractometers and measurement techniques of SRXRD were developed during the past decade 8 – 10 . Very small amounts of electron distributions were successfully observed in TiS 2 11 and LaB 6 12 using the diffractometers and techniques. The method can be applied to pure metal system.…”

Section: Introductionmentioning

confidence: 99%

Tightly binding valence electron in aluminum observed through X-ray charge density study

Sasaki¹,

Kasai²,

Nishibori³

2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

Accurate and high reciprocal resolution experimental structure factors of aluminum were determined from a synchrotron powder X-ray diffraction data measured at 30 K with sin θ/λ < 2.31 Å−1. The structure factors have small deviations from independent atom model in sin θ/λ < 0.83 Å−1. Theoretical structure factors were prepared using density functional theoretical calculations by full potential linearized augmented plane wave method. The deviation between experimental and theoretical data was also observed at around sin θ/λ ≈ 0.4 Å−1. The charge density was determined by an extended Hansen-Coppens multipole modeling using experimental and theoretical structure factors. Charge density maxima at tetrahedral site were observed in both experimental and theoretical deformation density. The charge-density difference peaks indicating directional bonding formation were observed in the difference density between experiment and theory. The present study reveals tight binding like character of valence electron of aluminum. The fact will provide a crucial information for development of high-performance aluminum alloy.

show abstract

Spatial distribution of electrons near the Fermi level in the metallic LaB6 through accurate X-ray charge density study

Cited by 17 publications

References 39 publications

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

Y₅Si₂B₈: A theoretically predicted new damage‐tolerant MAB phase with layered crystal structure

Tightly binding valence electron in aluminum observed through X-ray charge density study

Contact Info

Product

Resources

About

Spatial distribution of electrons near the Fermi level in the metallic LaB6 through accurate X-ray charge density study

Cited by 17 publications

References 39 publications

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

Y5Si2B8: A theoretically predicted new damage‐tolerant MAB phase with layered crystal structure

Tightly binding valence electron in aluminum observed through X-ray charge density study

Contact Info

Product

Resources

About

Y₅Si₂B₈: A theoretically predicted new damage‐tolerant MAB phase with layered crystal structure