NÉODYME

introduction

Numéro atomique: 60
Groupe: Aucun
Poids atomique: 144.24
Période: 6
Numero CAS: 7440-00-8

Classification

chalcogènes
Halogène
Gaz rare
lanthanides
actinides
Rare Earth Element
Groupe Platine Métal
Transuranium
Pas d'isotopes stables
Solide
Liquide
Gaz
Solide (prédit)

La description • Usages / Fonction

In 1841, Mosander, extracted from cerite a new rose-colored oxide, which he believed contained a new element. He named the element didymium,as it was an inseparable twin brother of lanthanum. In 1885 von Welsbach separated didymium into two new elemental components, neodymia andpraseodymia, by repeated fractionation of ammonium didymium nitrate. While the free metal is in misch metal, long known and used as a pyrophoricalloy for light flints, the element was not isolated in relatively pure form until 1925. Neodymium is present in misch metal to the extent of about 18%.It is present in the minerals monazite and bastnasite, which are principal sources of rare-earth metals. The element may be obtained by separatingneodymium salts from other rare earths by ion-exchange or solvent extraction techniques, and by reducing anhydrous halides such as Ndf3 with calciummetal. Other separation techniques are possible. The metal has a bright silvery metallic luster. Neodymium is one of the more reactive rare-earth metalsand quickly tarnishes in air, forming an oxide that spalls off and exposes metal to oxidation. The metal, therefore, should be kept under light mineral oil or sealed in a plastic material. Neodymium exists in two allotropic forms, with a transformation from a double hexagonal to a body-centered cubicstructure taking place at 863°C. Natural neodymium is a mixture of seven isotopes, one of which has a very long half-life. Twenty seven otherradioactive isotopes and isomers are recognized. Didymium, of which neodymium is a component, is used for coloring glass to make welder’s goggles.By itself, neodymium colors glass delicate shades ranging from pure violet through wine-red and warm gray. Light transmitted through such glassshows unusually sharp absorption bands. The glass has been used in astronomical work to produce sharp bands by which spectral lines may becalibrated. Glass containing neodymium can be used as a laser material to produce coherent light. Neodymium salts are also used as a colorant forenamels. The element is also being used with iron and boron to produce extremely strong magnets having energy densities as high as 27 to 35 milliongauss oersteds. These are the most compact magnets commercially available. The price of the metal is about $2/g. Neodymium has a low-to-moderateacute toxic rating. As with other rare earths, neodymium should be handled with care. 1

• "the magnet in a large wind turbine may contain 500 pounds or more of neodymium." 2
• "A neodymium-based magnet is many times stronger than a conventional ferrite magnet of the same size" 3
• "Hybrid cars would not exist without rare earth elements...neodymium magnets for their electric motors." 4
• "tint[s] sunglasses." 5
• "Some power tools rely on neodymium...magnets to shrink their motors." 6

Propriétés physiques

Point de fusion:7*  1021 °C = 1294.15 K = 1869.8 °F
Point d'ébullition:7* 3074 °C = 3347.15 K = 5565.2 °F
sublimation point:7 
Triple point:7 
Point critique:7 
Densité:8  7.01 g/cm3

* - at 1 atm

Configuration de l'électron

Configuration de l'électron:  *[Xe] 6s2 4f4
Bloque: f
Plus haut niveau d'énergie occupés: 6
Électrons de valence: 2

Nombres quantiques:

n = 4
ℓ = 3
m = 0
ms = +½

Bonding

Électronégativité (échelle de Pauling):9 1.14
Electropositivity (échelle de Pauling): 2.86
Fonction de travail:10 3.1 eV = 4.9662E-19 J

ionisation potentiel   eV 11  kJ/mol  
1 5.525    533.1
ionisation potentiel   eV 11  kJ/mol  
2 10.73    1035.3
ionisation potentiel   eV 11  kJ/mol  
3 22.1    2132.3
4 40.41    3899.0

Thermochimie

Chaleur spécifique: 0.190 J/g°C 12 = 27.406 J/mol°C = 0.045 cal/g°C = 6.550 cal/mol°C
Conductivité thermique: 16.5 (W/m)/K, 27°C 13
Température de fusion: 7.14 kJ/mol 14 = 49.5 J/g
Chaleur de vaporisation: 273 kJ/mol 15 = 1892.7 J/g
État de la matière Enthalpie de formation (ΔHf°)16 Entropy (S°)16 Gibbs Free Energy (ΔGf°)16
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 17.1 71.5464 0 0
(g) 78.3 327.6072 45.24 189.28416 69.9 292.4616

isotopes

Nuclide Masse 17 Demi vie 17 Spin nucléaire 17 Énergie de liaison
124Nd 123.95223(64)# 500# ms 0+ 1,000.48 MeV
125Nd 124.94888(43)# 600(150) ms 5/2(+#) 1,017.86 MeV
126Nd 125.94322(43)# 1# s [>200 ns] 0+ 1,025.93 MeV
127Nd 126.94050(43)# 1.8(4) s 5/2+# 1,034.00 MeV
128Nd 127.93539(21)# 5# s 0+ 1,051.39 MeV
129Nd 128.93319(22)# 4.9(2) s 5/2+# 1,059.46 MeV
130Nd 129.92851(3) 21(3) s 0+ 1,076.85 MeV
131Nd 130.92725(3) 33(3) s (5/2)(+#) 1,084.92 MeV
132Nd 131.923321(26) 1.56(10) min 0+ 1,092.99 MeV
133Nd 132.92235(5) 70(10) s (7/2+) 1,101.06 MeV
134Nd 133.918790(13) 8.5(15) min 0+ 1,118.45 MeV
135Nd 134.918181(21) 12.4(6) min 9/2(-) 1,126.52 MeV
136Nd 135.914976(13) 50.65(33) min 0+ 1,134.59 MeV
137Nd 136.914567(12) 38.5(15) min 1/2+ 1,142.66 MeV
138Nd 137.911950(13) 5.04(9) h 0+ 1,150.73 MeV
139Nd 138.911978(28) 29.7(5) min 3/2+ 1,158.81 MeV
140Nd 139.90955(3) 3.37(2) d 0+ 1,176.19 MeV
141Nd 140.909610(4) 2.49(3) h 3/2+ 1,184.26 MeV
142Nd 141.9077233(25) STABLE 0+ 1,192.33 MeV
143Nd 142.9098143(25) STABLE 7/2- 1,200.41 MeV
144Nd 143.9100873(25) 2.29(16)E+15 a 0+ 1,199.16 MeV
145Nd 144.9125736(25) STABLE 7/2- 1,207.23 MeV
146Nd 145.9131169(25) STABLE 0+ 1,215.30 MeV
147Nd 146.9161004(25) 10.98(1) d 5/2- 1,223.38 MeV
148Nd 147.916893(3) STABLE 0+ 1,231.45 MeV
149Nd 148.920149(3) 1.728(1) h 5/2- 1,230.20 MeV
150Nd 149.920891(3) 6.7(7)E+18 a 0+ 1,238.27 MeV
151Nd 150.923829(3) 12.44(7) min 3/2+ 1,246.35 MeV
152Nd 151.924682(26) 11.4(2) min 0+ 1,254.42 MeV
153Nd 152.927698(29) 31.6(10) s (3/2)- 1,262.49 MeV
154Nd 153.92948(12) 25.9(2) s 0+ 1,270.56 MeV
155Nd 154.93293(16)# 8.9(2) s 3/2-# 1,269.32 MeV
156Nd 155.93502(22) 5.49(7) s 0+ 1,277.39 MeV
157Nd 156.93903(21)# 2# s [>300 ns] 5/2-# 1,285.46 MeV
158Nd 157.94160(43)# 700# ms [>300 ns] 0+ 1,284.22 MeV
159Nd 158.94609(54)# 500# ms 7/2+# 1,292.29 MeV
160Nd 159.94909(64)# 300# ms 0+ 1,300.36 MeV
161Nd 160.95388(75)# 200# ms 1/2-# 1,299.11 MeV
Les valeurs marquées # ne sont pas purement dérivées des données expérimentales, mais au moins en partie des tendances systématiques. Spins avec de faibles arguments d'affectation sont entre parenthèses. 17

Abondance

Terre - composés Source: phosphates 18
Terre - Seawater: 0.0000028 mg/L 19
Terre -  Croûte:  41.5 mg/kg = 0.00415% 19
Terre -  Total:  690 ppb 20
Planète Mercure) -  Total:  530 ppb 20
Vénus -  Total:  723 ppb 20
chondrites - Total: 0.64 (relative to 106 atoms of Si) 21

composés

Information de sécurité


Fiche signalétique - ACI Alloys, Inc.

Pour plus d'informations

Liens externes:

Les magazines:
(1) Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, pp 136-145.

Sources

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:20.
(2) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 138.
(3) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 144.
(4) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 140.
(5) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 140.
(6) - Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, p 140.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(9) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(10) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1:132.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(12) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(13) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(14) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(15) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(16) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(17) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(18) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(19) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(20) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
(21) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.