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About Lutetium

Lutetium Bohr

Lutetium oxide was described independently by several different chemists in 1907: Georges Urbain in France, Carl Auer von Welsbach in Austria, and Charles James in America. All were working with an impure sample of ytterbium oxide. Urbain’s name for the new element contained in the oxide was based on the Greek name for Paris, and was the name ultimately retained for the element.

Lutetium is extremely rare, but does have a few commercial uses. It is added as a dopant to garnets used in speciality lenses and magneto-optical memory storage devices. Cerium-doped lutetium oxyorthosilicate (LSO) is one of the most effective materials for detectors in positron emission tomography (PET) scanners. Small quantities can also be used as catalysts in petroleum cracking and other industrial chemistry applications. Lutetium tantalate is the densest known stable white material that can be used as a host material for X-ray phosphors. Lutetium can also serve a dopant in a number of phosphors and scintillator crystals. Radioactive lutetium isotopes are used in radioactive dating and experimental cancer therapies.

Lutetium is a rare earth element and can theoretically be found in any rare earth containing mineral, but as a heavy rare earth element (HREE) it is more common in HREE-enriched minerals such as xenotime and euxenite. Additionally, lutetium is present in ion adsorption clays, which are a major source of HREEs due to their relative ease of processing, despite the low percentage quantities of rare earths they contain.

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Lutetium is the ideal host for x-ray phosphors because it produces the densest known white material, lutetium tantalate (LuTaO4). It is utilized as a dopant in matching lattice parameters of certain substrate garnet crystals, such as indium-gallium-garnet (IGG) crystals due its lack of a magnetic moment. Lutetium is High Purity (99.999%) Lutetium (Lu) Sputtering Target available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). High Purity (99.999%) Lutetium Oxide (Lu2O3) PowderElemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Lutetium oxide is available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Lutetium fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Lutetium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Lutetium Properties

Lutetium (Lu) atomic and molecular weight, atomic number and elemental symbolLutetium is a Block F, Group 3, Period 6 element. Lutetium Bohr ModelThe number of electrons in each of Lutetium's shells is 2, 8, 18, 32, 9, 2 and its electron configuration is [Xe] 4f15 5d1 6s2. In its elemental form, CAS 7439-94-3, lutetium has a silvery-white appearance. The lutetium atom has a radius of and its Van der Waals radius is Lutetium is the last member of the rare earth series. Unlike most rare earths it lacks Elemental Lutetiuma magnetic moment. It has the smallest metallic radius of any rare earth and it is one of the least abundant of the naturally occurring lanthanides. The most common source of commercially produced Lutetium is the mineral monazite. Lutetium was first discovered by discovered independently by several different chemists, all in 1907. The name Lutetium originates from the Latin word Luteti, a historic name for Paris.

Symbol: Lu
Atomic Number: 71
Atomic Weight: 174.97
Element Category: Lanthanide
Group, Period, Block: n/a, 6, f
Color: silvery white
Other Names: Lutezio, Lutécio
Melting Point: 1663°C, 3025.47°F, 1936.15 K
Boiling Point: 3402°C, 6155.6°F, 3675.15 K 
Density: 9.840 g/cm3
Liquid Density @ Melting Point: 9.3 g·cm3
Density @ 20°C: 9.8 g/cm3
Density of Solid: 9841 kg·m3
Specific Heat: 0.037 Cal/g/K @ 25°C
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 19.2
Heat of Vaporization (kJ·mol-1): 428
Heat of Atomization (kJ·mol-1): 427.37
Thermal Conductivity: 0.164 W/cm/K @ 298.2 K
Thermal Expansion: (r.t.) (poly) 9.9 µm/(m·K)
Electrical Resistivity: 79.0 µΩ-cm @ 25°C
Tensile Strength: N/A
Molar Heat Capacity: 26.86 J·mol-1·K-1
Young's Modulus: 68.6 GPa
Shear Modulus: 27.2 GPa
Bulk Modulus: 47.6 GPa
Poisson Ratio: 0.261
Mohs Hardness: N/A
Vickers Hardness: 1160 MPa
Brinell Hardness: 893 MPa
Speed of Sound: N/A
Pauling Electronegativity: 1.27
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: 1.14
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: 2.73
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 71
Protons: 71
Neutrons: 104
Electron Configuration: [Xe] 4f15 5d1 6s2
Atomic Radius: 174 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 187±8 pm
Covalent Radius (Å): 1.74
Van der Waals Radius: 221 pm
Oxidation States: 3, 2, 1 (weakly basic oxide)
Phase: Solid
Crystal Structure: hexagonal close-packed
Magnetic Ordering: paramagnetic
Electron Affinity (kJ·mol-1) 32.793
1st Ionization Energy: 523.52 kJ·mol-1
2nd Ionization Energy: 1341.16 kJ·mol-1
3rd Ionization Energy: 2022.29 kJ·mol-1
CAS Number: 7439-94-3
EC Number: 231-103-0
MDL Number: MFCD00011098
Beilstein Number: N/A
SMILES Identifier: [Lu]
InChI Identifier: InChI=1S/Lu
PubChem CID: 23929
ChemSpider ID: 22371
Earth - Total: 386 ppb
Mercury - Total: 297 ppb
Venus - Total: 405 ppb
Earth - Seawater (Oceans), ppb by weight: 0.00015
Earth - Seawater (Oceans), ppb by atoms: 0.000005
Earth -  Crust (Crustal Rocks), ppb by weight: 560
Earth -  Crust (Crustal Rocks), ppb by atoms: 70
Sun - Total, ppb by weight: 1
Sun - Total, ppb by atoms: 0.01
Stream, ppb by weight: 0.008
Stream, ppb by atoms: 0.00005
Meterorite (Carbonaceous), ppb by weight: 30
Meterorite (Carbonaceous), ppb by atoms: 3
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: 0.1
Universe, ppb by atom: 0.001
Discovered By: Georges Urbain and Carl Auer von Welsbach
Discovery Date: 1906
First Isolation: Carl Auer von Welsbach (1906)

Health, Safety & Transportation Information for Lutetium

Lutetium is not toxic in its elemental form, however, safety data for lutetium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Lutetium.

Safety Data
Material Safety Data Sheet MSDS
Signal Word Danger
Hazard Statements H228
Hazard Codes N/A
Risk Codes N/A
Safety Precautions N/A
RTECS Number N/A
Transport Information N/A
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)

Lutetium Isotopes

Naturally occurring lutetium (Lu) has 1 stable isotope, 175Lu.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
150Lu 149.97323(54)# 43(5) ms p to 149Yb; ß+ to 150Yb (2+) N/A 1160.09 -
151Lu 150.96758(43)# 80.6(19) ms ß+ to 151Yb (11/2-) N/A 1177.48 -
152Lu 151.96412(21)# 650(70) ms ß+ to 152Yb; ß+ + p to 151Tm (5-,6-) N/A 1185.56 -
153Lu 152.95877(22) 0.9(2) s ß+ to 153Yb; a to 149Tm 11/2- N/A 1202.96 -
154Lu 153.95752(22)# 1# s ß+ to 154Yb (2-) N/A 1211.04 -
155Lu 154.954316(22) 68.6(16) ms a to 151Tm; ß+ to 155Yb (11/2-) N/A 1219.11 -
156Lu 155.95303(8) 494(12) ms a to 152Tm; ß+ to 156Yb (2)- N/A 1227.19 -
157Lu 156.950098(20) 6.8(18) s ß+ to 157Yb; a to 153Tm (1/2+,3/2+) N/A 1235.27 -
158Lu 157.949313(16) 10.6(3) s ß+ to 158Yb; a to 154Tm 2- N/A 1252.67 -
159Lu 158.94663(4) 12.1(10) s ß+ to 159Yb; a to 155Tm 1/2+# N/A 1260.75 -
160Lu 159.94603(6) 36.1(3) s ß+ to 160Yb; a to 156Tm 2-# N/A 1268.82 -
161Lu 160.94357(3) 77(2) s ß+ to 161Yb 1/2+ N/A 1276.9 -
162Lu 161.94328(8) 1.37(2) min ß+ to 162Yb (1-) N/A 1284.98 -
163Lu 162.94118(3) 3.97(13) min ß+ to 163Yb 1/2(+) N/A 1293.06 -
164Lu 163.94134(3) 3.14(3) min ß+ to 164Yb 1(-) N/A 1301.14 -
165Lu 164.939407(28) 10.74(10) min ß+ to 165Yb 1/2+ N/A 1318.53 -
166Lu 165.93986(3) 2.65(10) min ß+ to 166Yb (6-) N/A 1326.61 -
167Lu 166.93827(3) 51.5(10) min ß+ to 167Yb 7/2+ N/A 1334.69 -
168Lu 167.93874(5) 5.5(1) min ß+ to 168Yb (6-) N/A 1342.77 -
169Lu 168.937651(6) 34.06(5) h EC to 169Yb 7/2+ N/A 1350.85 -
170Lu 169.938475(18) 2.012(20) d EC to 170Yb 0+ N/A 1358.93 -
171Lu 170.9379131(30) 8.24(3) d EC to 171Yb 7/2+ 2 1367.01 -
172Lu 171.939086(3) 6.70(3) d EC to 172Yb 4- 2.25 1375.09 -
173Lu 172.9389306(26) 1.37(1) y EC to 173Yb 7/2+ 2.3 1383.16 -
174Lu 173.9403375(26) 3.31(5) y EC to 174Yb (1)- 1.9 1381.93 -
175Lu 174.9407718(23) Observationally Stable - 7/2+ 2.2327 1390.01 97.41
176Lu 175.9426863(23) 38.5(7)E+9 y - 7- 3.19 1398.08 2.59
177Lu 176.9437581(23) 6.6475(20) d ß- to 177Hf 7/2+ 2.239 1406.16 -
178Lu 177.945955(3) 28.4(2) min ß- to 178Hf 1(+) N/A 1414.24 -
179Lu 178.947327(6) 4.59(6) h ß- to 179Hf 7/2(+) N/A 1422.32 -
180Lu 179.94988(8) 5.7(1) min ß- to 180Hf 5+ N/A 1430.4 -
181Lu 180.95197(32)# 3.5(3) min ß- to 181Hf (7/2+) N/A 1429.16 -
182Lu 181.95504(21)# 2.0(2) min ß- to 182Hf (0,1,2) N/A 1437.24 -
183Lu 182.95757(32)# 58(4) s ß- to 183Hf (7/2+) N/A 1445.32 -
184Lu 183.96091(43)# 20(3) s ß- to 184Hf (3+) N/A 1444.08 -