Error loading MacroEngine script (file: )

Latest News

 
 

Distribution of Rare Earths

Click on the graph below to see more detailed information.

Gadolinium (Gd) - 2.5%

Gadolinium is used in alloys of iron and chromium to improve resistance to high temperatures and oxidation. Gadolinium is used to make gadolinium yttrium garnets which have microwave applications. Gadolinium compounds are used as green phosphors in colour television picture tubes. Because of its magnetic properties, gadolinium is also used in intravenous radio-contrast agents in magnetic resonance imaging (MRI).

While gadolinium was first discovered in 1880, this metallic element was not used much until relatively recently. Today, gadolinium is used in manufacturing appliances and computer hardware, metalworking and medical imaging.

Terbium (Tb) - 0.5%

Terbium is used as a dopant in calcium fluoride, calcium tungstate and strontium molybdate, materials that are used in solid-state devices and as a crystal stabilizer of fuel cells which operate at elevated temperatures. As a component of Terfenol-D (an alloy that expands and contracts when exposed to magnetic fields more than any other alloy), terbium is of use in actuators, in naval sonar systems and in sensors.

Hybrid car engines have electric motors and all electric motors are based on magnets. These magnets need to retain their magnetism at high temperatures. Alloying neodymium with terbium and dysprosium produces such magnets. These magnets are also used in the electric motors of wind-turbines, where high temperatures are also generated.

The largest consumer of the world's terbium supply is in "green" phosphors (which are usually yellow). Terbium oxide is in fluorescent lamps and TV tubes. Terbium "green" phosphors (which fluoresce a brilliant lemon-yellow) are combined with divalent europium blue phosphors and trivalent europium red phosphors to provide "trichromatic" lighting technology, a high-efficiency white light used for standard illumination in indoor lighting.

Dysprosium (Dy) - 2.9%

Dysprosium is used, in conjunction with vanadium and other elements, in making laser materials and commercial lighting. Because of dysprosium's high thermal neutron absorption cross-section, dysprosium oxide-nickel cermets are used in neutron-absorbing control rods in nuclear reactors. Dysprosium-cadmium chalcogenides are sources of infrared radiation which is useful for studying chemical reactions. Because dysprosium and its compounds are highly susceptible to magnetization, they are employed in various data storage applications, such as in hard disks.

Neodymium-iron-boron magnets can have up to 6% of the neodymium substituted with dysprosium to raise the coercivity for demanding applications such as drive motors for hybrid electric vehicles. This substitution would require up to 100 grams of dysprosium per hybrid car produced. Based on Toyota's projected 2 million units per year, the use of dysprosium in applications such as this would quickly exhaust the available supply of the metal but for the huge TANBREEZ property. The dysprosium substitution may also be useful in other applications, as it improves the corrosion resistance of the magnets.

Holmium (Ho) - 0.6%

Holmium is found in the minerals monazite, gadolinite as well as eudialyte, and is usually commercially extracted using ion exchange techniques. As a result of its special magnetic properties, holmium is used in alloys for the production of magnets and as a flux concentrator for high magnetic fields. Holmium oxide is used as a yellow or red colouring for glass and cubic zirconia. Holmium isotopes are good neutron absorbers and are used in nuclear reactor control rods. It is also used in solid-state lasers for non-invasive medical procedures treating cancers and kidney stones.

Holmium laser at a human eye safe 2.08 microns allowing its use in a variety of medical and dental applications in both yttrium-aluminium-garnet (YAG) and yttrium-lanthanum-fluoride (YLF) solid state lasers. 

Erbium (Er) - 2.4%

Erbium's everyday uses are varied. It is commonly used as a photographic filter, and because of its resilience it is useful as a metallurgical additive. Other uses:

  • Used in nuclear technology in neutron-absorbing control rods.
  • When added to vanadium as an alloy, erbium lowers hardness and improves workability.
  •  Erbium oxide has a pink color, and is sometimes used as a colorant for glass, cubic zirconia and porcelain. The glass is then often used in sunglasses and cheap jewelry.
  • Erbium-doped optical silica-glass fibers are the active element in erbium-doped fiber amplifiers (EDFAs), which are widely used in optical communications.
  •  A large variety of medical applications (i.e. dermatology, dentistry) utilize erbium ion's 2940 nm emission (see Er:YAG laser), which is highly absorbed in water (absorption coefficient about 12000/cm). Such shallow tissue deposition of laser energy is necessary for laser surgery, and the efficient production of steam for laser enamel ablation in dentistry.

Thulium (Tm) - 0.3%

Thulium is the second least abundant of the lanthanides (promethium is only found in trace quantities on Earth). It is an easily workable metal with a bright silvery-gray luster. Despite its high price and rarity, thulium is used as the radiation source in portable X-ray devices and in solid-state lasers.

Ytterbium (Yb) - 2.0%

Ytterbium is found with other rare earth elements in several rare minerals. It is most often recovered commercially from monazite sand (0.03% ytterbium). The element is also found in euxenite and xenotime. Ytterbium is normally difficult to separate from other rare earths, but ion-exchange and solvent extraction techniques developed in the mid- to late 20th century have simplified separation. Known compounds of ytterbium are rare and have not yet been well characterized. The abundance of ytterbium in the Earth crust is about 3 mg/kg.

Ytterbium can be used as a dopant to help improve the grain refinement, strength, and other mechanical properties of stainless steel. Some ytterbium alloys have rarely been used in dentistry.

Currently ytterbium is investigated as a possible replacement for magnesium in high density pyrotechnic payloads for kinematic infrared decoy flares. As ytterbium(III) oxide has a significantly higher emissivity in the infrared range than magnesium oxide, a higher radiant intensity is obtained in ytterbium based payloads in comparison to those commonly based on Magnesium/Teflon/Viton(MTV).

Yttrium (Y) - 19.0%

Yttrium is used in many applications. Principal uses are in phosphors used in colour televisions and computer monitors, trichromatic fluorescent lights, temperature sensors, and X-ray intensifying screens. As a stabilizer in zirconia, yttrium is used in wear-resistant and corrosion-resistant cutting tools, seals and
bearings, high-temperature refractories for continuous casting nozzles, jet engine coatings, oxygen sensors in automobile engines, and simulant gemstones.

In electronics, yttrium-iron-garnets (YIG) are components in mUntitledicrowave radar to control high frequency signals. Yttrium is an important component in yttrium-aluminium garnets (YAG) laser crystals used in industrial cutting and welding, medical and dental surgical procedures, temperature and distance sensing, photoluminescence, photochemistry, digital communications, and nonlinear optics. Yttrium is also used in heating element alloys, superalloys, and high-temperature super-conductors.

 

Lutetium (Lu) - 0.3%

Lutetium is very expensive to obtain on useful quantities and therefore it has very few commercial uses. One commercial application has been as a pure beta emitter, using lutetium which has been exposed to neutron activation. A tiny amount of lutetium is added as a dopant to gadolinium gallium garnet (GGG), which is used in magnetic bubble memory devices.

Because of the rarity and high price, lutetium has very few commercial uses. However, stable lutetium can be used as catalysts in petroleum cracking in refineries and can also be used in alkylation, hydrogenation, and polymerization applications.

 Lu

 

Lanthanum (La) - 17.8%

Lanthanum metal is a key constituent of the mischmetal used in lighter flints, the first commercial application of rare earths. Lanthanum can be used in the production of green colour phosphors.

Lanthanum oxide (La2O3) improves the alkali resistance of glass, and is used in making special optical glasses, such as infrared absorbing glass. Lanthanum is also used as doping agents in camera and telescope lenses because of its high refractive index and low dispersion indices. Lanthanum has been used to increase the refractive index of glass, for use in lenses, for over 30 years. 

Lanthanum is an intermetallic component of Nickel Metal Hydride (NiMH) batteries which are used by several electric automobile producers, are used in laptop computers, and other hand-held electronic devices. Lanthanum is also used in hydrogen storage fuel cell materials for stationary and automotive where they
can store up to 400 times their own volume of hydrogen gas in a reversible adsorption process.

Cerium (Ce) - 33.3%

A major technological application for Cerium (III) oxide is a catalytic converter for the reduction of CO emissions in the exhaust gases from motor vehicles. In particular, cerium oxide is added into Diesel fuels. Another important use of the cerium oxide is a hydrocarbon catalyst in self cleaning ovens, incorporated into oven walls and as a petroleum cracking catalyst in petroleum refining.

Cerium (IV) oxide is considered one of the most efficient agents for precision polishing of optical components. Cerium compounds are also used in the manufacture of glass, both as a component and as a decolorizer. For example, cerium (IV) oxide in combination with titanium (IV) oxide gives a golden yellow color to glass; it also allows for selective absorption of ultraviolet light in glass. Cerium oxide has a high refractive index and is added to enamel to make it more opaque.

Praseodymium (Pr) - 3.2%

Praseodymium can be used as a substitute for neodymium in super magnets.  PrNi5 alloy also demonstrates magneto-caloric characteristics. 

Praseodymium is a doping agent in fibre optic cables where the cable is used as a signal amplifier. Praseodymium salts are used to give glass, enamels and cubic zirconia a yellow colour. As a component of didymium, praseodymium is used to make certain types of welder's and glass blower's goggles and other UV protective glasses 

Praseodymium forms the core of carbon arc lights, which are used in the motion picture industry for studio lighting and projector lights.  It is also used in CAT scan scintillators.

Praseodymium's primary use is as an alloying agent with magnesium to create high-strength metals used in aircraft engines.

Neodymium (Nd) - 12%

Neodymium magnets (Nd2Fe14B) or 'neo-magnets' are the strongest permanent magnets known. Although mechanically fragile, they are cheaper, lighter, and stronger than the better known, rare earth, samarium-cobalt magnet. Neo-magnets appear in products such as microphones, loudspeakers, in-ear headphones (ear buds and hearing aids), guitar pick-ups, computer hard drives, and "voice coils" for reading computer hard drives.

Neodymium glass is becoming widely used in incandescent light bulbs to provide a more 'natural' light, as it filters out yellow wavelengths and results in a whiter light more like sunlight.

Samarium (Sm) - 2.3%

In the 1970s samarium became a key ingredient for a super magnet - the samarium cobalt magnet. Today, permanent magnets dominate rare earth technology because of their ability to provide greater magnet power in vastly smaller sizes.

Magnetic technology rates as the most important use of rare earth elements due to its many uses in energy and military applications.

Radioactive samarium is used to kill cancer cells in the treatment of lung cancer, prostate cancer, breast cancer and osteosarcoma.

Samarium-149 is used in the control rods of nuclear reactors. Its advantage compared to competing materials, such as boron and cadmium, is stability of absorption - most of the fusion and decay products of samarium-149 are other isotopes of samarium which are also good neutron absorbers.

Europium (Eu) - 0.3%

It is a dopant in some types of glass in lasers and other optoelectronic devices. Europium oxide (Eu2O3) is widely used as a red phosphor in television sets and fluorescent lamps, and as an activator for yttrium-based phosphors.

Europium is also used in the manufacture of fluorescent glass. One of the more common persistent after-glow phosphors besides copper doped zinc sulfide is europium doped strontium aluminate. Europium fluorescence is used to interrogate bio molecular interactions in drug-discovery screens. It is also used in the anti-counterfeiting phosphors in Euro banknotes.