Indium

Indium, ₄₉In
Indium
Pronunciation	/ˈɪndiəm/ (IN-dee-əm)
Appearance	silvery lustrous gray
Standard atomic weight Ar°(In)
	114.818±0.001; 114.82±0.01 (abridged);
Indium in the periodic table
	cadmium ← indium → tin
Atomic number (Z)	49
Group	group 13 (boron group)
Period	period 5
Block	p-block
Electron configuration	[Kr] 4d10 5s2 5p1
Electrons per shell	2, 8, 18, 18, 3
Physical properties
Phase at STP	solid
Melting point	429.7485 K (156.5985 °C, 313.8773 °F)
Boiling point	2345 K (2072 °C, 3762 °F)
Density (at 20° C)	7.290 g/cm3
when liquid (at m.p.)	7.02 g/cm3
Triple point	429.7445 K, ~1 kPa
Heat of fusion	3.281 kJ/mol
Heat of vaporization	231.8 kJ/mol
Molar heat capacity	26.74 J/(mol·K)
Atomic properties
Oxidation states	−5, −2, −1, 0, +1, +2, +3 (an amphoteric oxide)
Electronegativity	Pauling scale: 1.78
Ionization energies	1st: 558.3 kJ/mol ; 2nd: 1820.7 kJ/mol ; 3rd: 2704 kJ/mol ; ;
Atomic radius	empirical: 167 pm
Covalent radius	142±5 pm
Van der Waals radius	193 pm
	Spectral lines of indium
Other properties
Natural occurrence	primordial
Crystal structure	body-centered tetragonal (tI2)
Lattice constants	a = 325.16 pm; c = 494.71 pm (at 20 °C)
Thermal expansion	32.2×10−6/K (at 20 °C)
Thermal conductivity	81.8 W/(m⋅K)
Electrical resistivity	83.7 nΩ⋅m (at 20 °C)
Magnetic ordering	diamagnetic
Molar magnetic susceptibility	−64.0×10−6 cm3/mol (298 K)
Young's modulus	11 GPa
Speed of sound thin rod	1215 m/s (at 20 °C)
Mohs hardness	1.2
Brinell hardness	8.8–10.0 MPa
CAS Number	7440-74-6
History
Discovery	Ferdinand Reich and Hieronymous Theodor Richter (1863)
First isolation	Hieronymous Theodor Richter (1864)
Isotopes of indium v; e;
	Category: Indium; view; talk; edit; \| references

Indium is a chemical element; it has symbol In and atomic number 49. It is a silvery-white post-transition metal and one of the softest elements. Chemically, indium is similar to gallium and thallium, and its properties are largely intermediate between the two.^[10] It was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods and named for the indigo blue line in its spectrum.^[11]

Indium is a technology-critical element used primarily in the production of flat-panel displays as indium tin oxide (ITO), a transparent and conductive coating applied to glass.^[12]^[13]^[14] Indium is also used in the semiconductor industry,^[15] in low-melting-point metal alloys such as solders and soft-metal high-vacuum seals. It is produced exclusively as a by-product during the processing of the ores of other metals, chiefly from sphalerite and other zinc sulfide ores.^[16]

Indium has no biological role and its compounds are toxic when inhaled or injected into the bloodstream, although they are poorly absorbed following ingestion.^[17]^[18]

^ "Standard Atomic Weights: Indium". CIAAW. 2011.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
^ ^a ^b ^c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
^ Mangum, B. W. (1989). "Determination of the Indium Freezing-point and Triple-point Temperatures". Metrologia. 26 (4): 211. Bibcode:1989Metro..26..211M. doi:10.1088/0026-1394/26/4/001.
^ Unstable In(0) carbonyls and clusters have been detected, see [1], p. 6.
^ Guloy, A. M.; Corbett, J. D. (1996). "Synthesis, Structure, and Bonding of Two Lanthanum Indium Germanides with Novel Structures and Properties". Inorganic Chemistry. 35 (9): 2616–22. doi:10.1021/ic951378e. PMID 11666477.
^ Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
^ W. M. Haynes (2010). David R. Lide (ed.). CRC Handbook of Chemistry and Physics: A Ready-reference Book of Chemical and Physical Data. CRC Press. ISBN 978-1-4398-2077-3.
^ Cite error: The named reference Venetskii was invoked but never defined (see the help page).
^ Wang, Zhaokui; Naka, Shigeki; Okada, Hiroyuki (30 November 2009). "Influence of ITO patterning on reliability of organic light emitting devices". Thin Solid Films. 518 (2): 497–500. Bibcode:2009TSF...518..497W. doi:10.1016/j.tsf.2009.07.029. ISSN 0040-6090.
^ Chen, Zhangxian; Li, Wanchao; Li, Ran; Zhang, Yunfeng; Xu, Guoqin; Cheng, Hansong (2013-10-28). "Fabrication of Highly Transparent and Conductive Indium–Tin Oxide Thin Films with a High Figure of Merit via Solution Processing". Langmuir. 29 (45): 13836–13842. doi:10.1021/la4033282. ISSN 0743-7463. PMID 24117323.
^ Cite error: The named reference :0 was invoked but never defined (see the help page).
^ Nirmal, D.; Ajayan, J. (2019-01-01), Kaushik, Brajesh Kumar (ed.), "Chapter 3 - InP-Based High-Electron-Mobility Transistors for High-Frequency Applications", Nanoelectronics, Advanced Nanomaterials, Elsevier, pp. 95–114, doi:10.1016/b978-0-12-813353-8.00012-9, ISBN 978-0-12-813353-8, retrieved 2023-12-08
^ Cite error: The named reference Frenzel-2017 was invoked but never defined (see the help page).
^ Cite error: The named reference Sauler was invoked but never defined (see the help page).
^ Cite error: The named reference toxic was invoked but never defined (see the help page).

Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).

[1] "Standard Atomic Weights: Indium". CIAAW. 2011.

[CIAAW2021-2] Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.

[Arblaster_2018-3] Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.

[4] Mangum, B. W. (1989). "Determination of the Indium Freezing-point and Triple-point Temperatures". Metrologia. 26 (4): 211. Bibcode:1989Metro..26..211M. doi:10.1088/0026-1394/26/4/001.

[5] Unstable In(0) carbonyls and clusters have been detected, see [1], p. 6.

[6] Guloy, A. M.; Corbett, J. D. (1996). "Synthesis, Structure, and Bonding of Two Lanthanum Indium Germanides with Novel Structures and Properties". Inorganic Chemistry. 35 (9): 2616–22. doi:10.1021/ic951378e. PMID 11666477.

[8] Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.

[9] Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.

[NUBASE2020-10] Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

[Ph.D.Lide2010-11] W. M. Haynes (2010). David R. Lide (ed.). CRC Handbook of Chemistry and Physics: A Ready-reference Book of Chemical and Physical Data. CRC Press. ISBN 978-1-4398-2077-3.

[Venetskii-12] Cite error: The named reference Venetskii was invoked but never defined (see the help page).

[13] Wang, Zhaokui; Naka, Shigeki; Okada, Hiroyuki (30 November 2009). "Influence of ITO patterning on reliability of organic light emitting devices". Thin Solid Films. 518 (2): 497–500. Bibcode:2009TSF...518..497W. doi:10.1016/j.tsf.2009.07.029. ISSN 0040-6090.

[14] Chen, Zhangxian; Li, Wanchao; Li, Ran; Zhang, Yunfeng; Xu, Guoqin; Cheng, Hansong (2013-10-28). "Fabrication of Highly Transparent and Conductive Indium–Tin Oxide Thin Films with a High Figure of Merit via Solution Processing". Langmuir. 29 (45): 13836–13842. doi:10.1021/la4033282. ISSN 0743-7463. PMID 24117323.

[:0-15] Cite error: The named reference :0 was invoked but never defined (see the help page).

[16] Nirmal, D.; Ajayan, J. (2019-01-01), Kaushik, Brajesh Kumar (ed.), "Chapter 3 - InP-Based High-Electron-Mobility Transistors for High-Frequency Applications", Nanoelectronics, Advanced Nanomaterials, Elsevier, pp. 95–114, doi:10.1016/b978-0-12-813353-8.00012-9, ISBN 978-0-12-813353-8, retrieved 2023-12-08

[Frenzel-2017-17] Cite error: The named reference Frenzel-2017 was invoked but never defined (see the help page).

[Sauler-18] Cite error: The named reference Sauler was invoked but never defined (see the help page).

[toxic-19] Cite error: The named reference toxic was invoked but never defined (see the help page).

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