Theoretical and experimental investigation of point defects in cubic boron nitride

MRS Advances ◽  
2017 ◽  
Vol 2 (29) ◽  
pp. 1545-1550 ◽  
Author(s):  
Nicholas L. McDougall ◽  
Jim G. Partridge ◽  
Desmond W. M. Lau ◽  
Philipp Reineck ◽  
Brant C. Gibson ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Optical Emission ◽  
Wide Band ◽  
Wide Band Gap ◽  
Edge Structure ◽  
X Ray ◽  
Substitutional Defects ◽  
X Ray Absorption ◽  
Annealing Experiments

ABSTRACTCubic boron nitride (cBN) is a synthetic wide band gap material that has attracted attention due to its high thermal conductivity, optical transparency and optical emission. In this work, defects in cBN have been investigated using experimental and theoretical X-ray absorption near edge structure (XANES). Vacancy and O substitutional defects were considered, with O substituted at the N site (ON) to be the most energetically favorable. All defects produce unique signatures in either the B or N K-edges and can thus be identified using XANES. The calculations coupled with electron-irradiation / annealing experiments strongly suggest that ON is the dominant defect in irradiated cBN and remains after annealing. This defect is a likely source of optical emission in cBN.

Quantitative phase analysis of cubic boron nitride based composites by X-ray absorption near edge structure

2007 ◽  
Vol 62 (5) ◽  
pp. 461-469 ◽  
Author(s):  
Edyta Piskorska ◽  
Krystyna Lawniczak-Jablonska ◽  
Roman Minikayev ◽  
Anna Wolska ◽  
Wojciech Paszkowicz ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Phase Analysis ◽  
Cubic Boron Nitride ◽  
Quantitative Phase Analysis ◽  
Edge Structure ◽  
X Ray ◽  
Quantitative Phase ◽  
X Ray Absorption

X-ray absorption studies of phase formation in a Ti/TiN coating on cubic boron nitride

2004 ◽  
Vol 362 (1-2) ◽  
pp. 171-177 ◽  
Author(s):  
E Piskorska ◽  
K Lawniczak-Jablonska ◽  
I.N Demchenko ◽  
E Benko ◽  
E Welter
Keyword(s):  
Boron Nitride ◽  
Phase Formation ◽  
Cubic Boron Nitride ◽  
Tin Coating ◽  
X Ray ◽  
Absorption Studies ◽  
X Ray Absorption

Cathodoluminescence, X-ray excited optical luminescence, and X-ray absorption near-edge structure studies of ZnO nanostructures

2012 ◽  
Vol 90 (3) ◽  
pp. 298-305 ◽  
Author(s):  
Olga Lobacheva ◽  
Patricia L. Corcoran ◽  
Michael W. Murphy ◽  
Jun Young Peter Ko ◽  
Tsun-Kong Sham
Keyword(s):  
Gas Flow ◽  
Branching Ratio ◽  
Optical Emission ◽  
Zno Nanostructures ◽  
Edge Structure ◽  
X Ray ◽  
Synthesis Parameters ◽  
Optical Luminescence ◽  
Carrier Gas Flow ◽  
X Ray Absorption

ZnO nanostructures of various morphologies and crystallinities were fabricated by thermal evaporation from Zn powder in a tube furnace in the presence of oxygen. It was found that the morphology of ZnO nanostructures was affected by synthesis parameters, such as growth temperature, carrier gas flow, and the presence of catalyst on the surface of the substrate. Representative ZnO nanostructures were studied by X-ray excited optical luminescence (XEOL) and cathodoluminescence (CL) methods. The luminescence from these samples exhibits a morphology dependence of the branching ratio of the near band gap (NBG) emission in the UV and defect emission in the green (GE). The appearance of the optical emission also depends on the excitation method. X-ray absorption near-edge structures (XANES) at the O K-edge and Zn L-edge are also presented and their implications discussed.

Characterization of Local Chemistry and Disorder in Synthetic and Natural α-Al2O3Materials by X-ray Absorption Near-Edge Structure Spectroscopy

1998 ◽  
Vol 31 (6) ◽  
pp. 890-898 ◽  
Author(s):  
Annibale Mottana ◽  
Takatoshi Murata ◽  
Augusto Marcelli ◽  
Giancarlo Della Ventura ◽  
Giannantonio Cibin ◽  
...  
Keyword(s):  
Short Range ◽  
Light Element ◽  
Detectable Effect ◽  
Edge Structure ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Substitutional Defects ◽  
X Ray Absorption ◽  
Made In

X-ray absorption fine spectra at the AlKedge were measured experimentally and calculated theoreticallyviathe multiple-scattering formalism for chemically pure and physically perfect synthetic α-Al2O3(α-alumina), natural ruby/sapphire (corundum) and a series of artificial corundums produced for technical purposes and used as geochemical standards. The AlK-edge spectra differ, despite the identical coordination (short-range arrangement) assumed by O around Al, and vary slightly in relation to the slightly different chemistries of the materials (substitutional defects) as well as on account of the location taken by foreign atoms in the structural lattices (positional defects). A quantitative treatment of the observed changes is made in terms of short-range distortion of the coordination polyhedron and of medium- to long-range modifications in the overall structure, both induced by substitutions. In some technical corundums, the impurities of admixed β-alumina, where Al is both in fourfold and sixfold coordination, produce another small but detectable effect on AlKedges. Therefore, XAFS spectroscopy proves its potential for both measuring a light element such as Al and detecting minor coordination changes and dilute substitutions (∼1–3 wt% as oxide) of the absorber by other atoms, at least under the favourable conditions occurring in this system.

scholarly journals The electronic properties and band-gap discontinuities at the cubic boron nitride/diamond hetero-interface

RSC Advances ◽  
2019 ◽  
Vol 9 (15) ◽  
pp. 8435-8443 ◽  
Author(s):  
Dehe Zhao ◽  
Wei Gao ◽  
Yujing Li ◽  
Yuyuan Zhang ◽  
Hong Yin
Keyword(s):  
Boron Nitride ◽  
Band Gap ◽  
Electronic Properties ◽  
Functional Properties ◽  
Cubic Boron Nitride ◽  
Electronic States ◽  
Wide Band ◽  
Hybrid Structures ◽  
Wide Band Gap

Clarifying the electronic states and structures of the c-BN/diamond interface is of extreme importance for bundling these two different wide-band gap materials in order to synthesize hybrid structures with new functional properties.

X-ray absorption studies on cubic boron nitride thin films

2007 ◽  
Vol 101 (1) ◽  
pp. 013710 ◽  
Author(s):  
X. T. Zhou ◽  
T. K. Sham ◽  
W. J. Zhang ◽  
C. Y. Chan ◽  
I. Bello ◽  
...  
Keyword(s):  
Thin Films ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
X Ray ◽  
Absorption Studies ◽  
X Ray Absorption

Transparent Nano-Glass-Ceramic for Photonic Applications - Distribution of RE-Doping Elements in the Fluoride Nano-Crystals Analysed by XAS and HR-TEM

2014 ◽  
Vol 90 ◽  
pp. 111-120 ◽  
Author(s):  
Araceli de Pablos-Martín ◽  
Maria J. Pascual ◽  
Alicia Durán
Keyword(s):  
Glass Ceramics ◽  
Optical Emission ◽  
Elemental Distribution ◽  
Edge Structure ◽  
X Ray ◽  
Nano Crystalline ◽  
Re Elements ◽  
X Ray Absorption ◽  
Down Conversion ◽  
O 10

Rare-earth (RE) ions-doped oxyfluoride transparent glass-ceramics containing nano-crystalline phases with very low phonon energies like LaF3, NaLaF4 and KLaF4 combine the superior optical performance of low phonon energy phases with the high mechanical, chemical and thermal stability of oxide silicates. The insertion of the doping RE ions in the fluoride nanocrystals enhances the radiative optical emission processes currently focused on up- and down-conversion emissions. Thus, a key point is to identify and quantify the RE ions in the fluoride nano-crystals. In this contribution an oxyfluoride glass and the corresponding glass-ceramics of composition 55 SiO2. 20 Al2O3.15 Na2O.10 LaF3 mol % doped with 1 mol % Tm2O3 is presented. The Tm3+ incorporation in the precipitated LaF3 nano-crystals has been analysed by two different techniques. Firstly, TEM and Energy Dispersive X-Ray Spectroscopy (EDXS) were used to perform elemental distribution mappings of RE elements that allow to directly localising RE ions in the glass and glass-ceramics. Additionally, X-ray absorption spectroscopy (XAS) measurements were performed to analyse the distribution and first coordination sphere of Tm3+ ions in the glass and glass–ceramics by using X-ray absorption near edge structure spectroscopy (XANES) and extended absorption X-ray fine structure spectroscopy (EXAFS), which have allow to quantify the Tm3+ incorporation in the LaF3 nano-crystals.

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