Utente:Grasso Luigi/sanbox1/Arseniuro di boro
| Arseniuro di boro | |
|---|---|
 | |
| Nome IUPAC | |
| Arseniuro di boro | |
| Caratteristiche generali | |
| Formula bruta o molecolare | BAs |
| Massa molecolare (u) | [3] |
| Numero CAS | |
| PubChem | 10285774 |
| SMILES | [B][As] |
| Proprietà chimico-fisiche | |
| Solubilità in acqua | 0.4% (20°C)[4] |
| Tensione di vapore (Pa) a 295 K | 19 mmHg (20°C)[4] |
| Dati farmacologici | |
| Categoria farmacoterapeutica | antibiotici, tetracicline |
| Modalità di somministrazione | orale |
| Indicazioni di sicurezza | |
| Simboli di rischio chimico | |
 
| |
| attenzione | |
| Frasi H | --- |
| Consigli P | ---[5]---[6] |
Boron arsenide is a chemical compound involving boron and arsenic, usually with a chemical formula BAs. Other boron arsenide compounds are known, such as the subarsenide Template:Chem2. Chemical synthesis of cubic BAs is very challenging and its single crystal forms usually have defects.[7]
Proprietà[modifica | modifica wikitesto]
BAs is a cubic (sphalerite) semiconductor in the III-V family with a lattice constant of 0.4777 nm and an indirect band gap of 1.82 eV.[8] Cubic BAs is reported to decompose to the subarsenide B12As2 at temperatures above 920 °C.[9] Boron arsenide has a melting point of 2076 °C. The thermal conductivity of BAs is very high: around 1300 W/(m·K) at 300 K.[7]
The basic physical properties of cubic BAs have been experimentally measured:[8] Band gap (1.82 eV), optical refractive index (3.29 at wavelength 657 nm), elastic modulus (326 GPa), shear modulus, Poisson's ratio, thermal expansion coefficient (3.85×10−6/K), and heat capacity. It can be alloyed with gallium arsenide to produce ternary and quaternary semiconductors.[10]
BAs has high electron and hole mobility, >1000 cm2/V/second, unlike silicon which has high electron mobility, but low hole mobility.[11]
Subarseniuro di boro[modifica | modifica wikitesto]
Boron arsenide also occurs as subarsenides, including the icosahedral boride Template:Chem2. It belongs to R3m space group with a rhombohedral structure based on clusters of boron atoms and two-atom As–As chains. It is a wide-bandgap semiconductor (3.47 eV) with the extraordinary ability to "self-heal" radiation damage.[12] This form can be grown on substrates such as silicon carbide.[13] Another use for solar cell fabrication[10][14] was proposed, but it is not currently used for this purpose.
Applicazioni[modifica | modifica wikitesto]
Boron arsenide is most attractive for use in electronics thermal management.[15] Experimental integration with gallium nitride transistors to form GaN-BAs heterostructures has been demonstrated and shows better performance than the best GaN HEMT devices on silicon carbide or diamond substrates. Manufacturing BAs composites was developed as highly conducting and flexible thermal interfaces.[16]
First-principles calculations have predicted that the thermal conductivity of cubic BAs is remarkably high, over 2,200 W/(m·K) at room temperature, which is comparable to that of diamond and graphite.[17] Subsequent measurements yielded a value of only 190 W/(m·K) due to the high density of defects.[18][19] More recent first-principles calculations incorporating four-phonon scattering predict a thermal conductivity of 1400 W/(m·K).[20] Later, defect-free boron arsenide crystals have been experimentally realized and measured with an ultrahigh thermal conductivity of 1300 W/(m·K),[7] consistent with theory predictions. Crystals with small density of defects have shown thermal conductivity of 900–1000 W/(m·K).[21][22]
Note[modifica | modifica wikitesto]
- ^ (EN) PubChem Compound, AC1L1C0X - Compound Summary, su pubchem.ncbi.nlm.nih.gov, National Center for Biotechnology Information, 25 Marzo 2005. URL consultato il 13 Ottobre 2011.
- ^ (EN) Chemical Entities of Biological Interest, methanediyl (CHEBI:29357), su ebi.ac.uk, EBI (UK), 14-01-2009. URL consultato il 02-01-2012.
- ^ (EN) IUPAC Commission on Isotopic Abundances and Atomic Weights., Atomic weights of the elements 2017, su Queen Mary University of London.
- ^ a b (EN) NIOSH Pocket Guide to Chemical Hazards, 1,1,2-Trichloroethane, su cdc.gov, NIOSH.
- ^ Scheda del composto su IFA-GESTIS
- ^ Scheda del composto su ARPA
- ^ a b c Experimental observation of high thermal conductivity in boron arsenide, in Science, vol. 361, n. 6402, 2018, pp. 575–578, DOI:10.1126/science.aat5522.
- ^ a b Basic physical properties of cubic boron arsenide, in Applied Physics Letters, vol. 115, n. 12, 2019, p. 122103, DOI:10.1063/1.5116025.
- ^ Preparation and Properties of Boron Arsenide Films, in Journal of the Electrochemical Society, vol. 121, n. 3, 1974, p. 412, DOI:10.1149/1.2401826.
- ^ a b BGaInAs alloys lattice matched to GaAs, in Applied Physics Letters, vol. 76, n. 11, 2000, p. 1443, DOI:10.1063/1.126058.
- ^ (EN) Jungwoo Shin, High ambipolar mobility in cubic boron arsenide, in Science, vol. 377, n. 6604, 22 luglio 2022, pp. 437–440, DOI:10.1126/science.abn4290.
- ^ Defect clustering and self-healing of electron-irradiated boron-rich solids, in Physical Review B, vol. 51, n. 17, 1995, pp. 11270–11274, DOI:10.1103/PhysRevB.51.11270.
- ^ Single-Crystalline B12As2 on m-plane (1100) 15R-SiC, in Applied Physics Letters, vol. 92, n. 23, 2008, DOI:10.1063/1.2945635.
- ^ Boone, J. L. and Vandoren, T. P. (1980) Boron arsenide thin film solar cell development, Final Report, Eagle-Picher Industries, Inc., Miami, OK. abstract.
- ^ Integration of boron arsenide cooling substrates into gallium nitride devices, in Nature Electronics, vol. 4, n. 6, 2021, pp. 416–423, DOI:10.1038/s41928-021-00595-9..
- ^ Flexible thermal interface based on self-assembled boron arsenide for high-performance thermal management, in Nature Communications, vol. 12, n. 1, 2021, p. 1284, DOI:10.1038/s41467-021-21531-7..
- ^ An unlikely competitor for diamond as the best thermal conductor, Phys.org news (July 8, 2013)
- ^ Experimental study of the proposed super-thermal-conductor: BAs (PDF), in Applied Physics Letters, vol. 106, n. 7, 2015, p. 074105, DOI:10.1063/1.4913441.
- ^ Antisite Pairs Suppress the Thermal Conductivity of BAs, in Physical Review Letters, vol. 121, n. 10, 6 September 2018, DOI:10.1103/PhysRevLett.121.105901.
- ^ Four-phonon scattering significantly reduces intrinsic thermal conductivity of solids, in Physical Review B, vol. 96, n. 16, 2017, p. 161201, DOI:10.1103/PhysRevB.96.161201.
- ^ High thermal conductivity in cubic boron arsenide crystals, in Science, vol. 361, n. 6402, 2018, pp. 579–581, DOI:10.1126/science.aat8982.
- ^ Unusual high thermal conductivity in boron arsenide bulk crystals, in Science, vol. 361, n. 6402, 2018, pp. 582–585, DOI:10.1126/science.aat7932.
Collegamenti esterni[modifica | modifica wikitesto]
- 2020 paper by Malica and Dal Corso - Temperature dependent elastic constants and thermodynamic properties of BAs: An ab initio investigation
- Matweb data
- R. B. King, Boron Chemistry at the Millennium, New York, Elsevier, 1999, ISBN 0-444-72006-5.
- P. D. Ownby, Ordered Boron Arsenide, in Journal of the American Ceramic Society, vol. 58, 7–8, 1975, pp. 359–360, DOI:10.1111/j.1151-2916.1975.tb11514.x.