Basic knowledge of Rare Earth -3

Lanthanum
The element lanthanum "was named in 1839, when there is a call" mo sander "swedes ceria was found to contain other elements, he borrowed from Greek the word" hide "the element named" lanthanum ". Since then, lanthanum has ascended to the historical stage.

Lanthanum has a very wide range of applications, such as applied to piezoelectric materials, electric materials, thermoelectric materials, magnetic resistance materials, luminescence materials (powder), h ydrogen storage materials, optical glass, laser materials, all kinds of alloy materials, etc. She has also been used in the preparation of a number of catalysts for organic chemicals, using lanthanum for conversion of agricultural films, and in foreign countries, scientists have assigned lanthanum to the "super calcium" of crops.

Cerium 
The element "cerium" was discovered and named in 1803 by German clauseaus, the Swede, usbozili, and sisheng geer, in honor of the asteroid, Ceres Ceres, which was discovered in 1801.

Cerium is widely used in (1) cerium as glass additive, which can absorb ultraviolet and infrared ray and has been widely used in automobile glass. It can not only protect the ultraviolet ray, but also reduce the temperature in the car, thus saving air conditioning power. Since 1997, the Japanese auto glass has been added to cerium oxide. The cerium oxide used in automobile glass in 1996 is at least 2000 tons and the United States is about 1000 tons.

(2) it is currently applying cerium to vehicle exhaust purification catalyst, which can effectively prevent a large number of automobile exhaust from being discharged into the air. The United States accounts for a third of total rare earth consumption.

(3) cerium sulphide can replace lead, cadmium and other metals that are harmful to the environment and human. It can be used in pigment, and can be used in coatings, ink and paper industries. Currently leading the way is the Ronald Planck company in France.

(4) Ce:LiSAF laser system is a solid-state laser developed in the United States. It can be used to detect biological weapons by monitoring the concentration of tryptophan, which can also be used in medicine. Cerium is widely used in almost all fields of rare earth application. Such as polishing powder, h ydrogen storage material, thermoelectric materials, cerium tungsten electrode, ceramic capacitors and piezoelectric ceramic, cerium silicon carbide abrasive, fuel cell materials, gasoline catalyst, some permanent magnetic material, all kinds of alloy steel and non-ferrous metals, etc.

Praseodymium
About 160 years ago, the swedes mo sander from lanthanum discovered a new element, but it is not a single element, mo Thornton found the nature of this element is very similar with lanthanum, will its entitled "praseodymium neodymium". "Praseodymium" is the Greek word for "twins". Around for more than 40 years, is the invention gaideng veil in 1885, Austrian Wells Bach successfully isolated from "neodymium praseodymium" out of the two elements, one named "nd", the other is named "pr". The twins have been separated and the praseodymium has a wide range of talents.

Praseodymium is a large amount of rare earth elements, which are mainly used in glass, ceramics and magnetic materials. Praseodymium (1) is widely used in building ceramics and ceramics for daily use, its mixed with ceramic glaze glaze, also can make the glaze alone paint, paint made of pale yellow, tonal and pure and elegant. (2) to make permanent magnets.

The use of cheap praseodymium metal to replace the pure neodymium metal to make permanent magnetic materials, its anti-oxygen performance and mechanical properties are obviously improved, can be processed into various shapes of magnets. Widely used in various electronic devices and motors. (3) oil catalytic cracking. The catalytic activity, selectivity and stability of the catalyst can be improved by adding praseodymium to the zeolite. China began to devote to industrial use in the 1970s, and the dosage was increasing. (4) praseodymium can also be used in abrasive polishing. In addition, the use of praseodymium in the optical fiber field is becoming more and more widespread.

Neodymium
 
Along with the birth of the praseodymium element, neodymium element also came into being, the arrival of neodymium was active in the field of rare earth, playing an important role in the field of rare earth, and left and right the rare earth market.

With its unique position in the field of rare earth, neodymium has been the focus of the market for many years. The largest user of metal neodymium is the nd-fed-boron permanent magnet material. The invention of ndfeb permanent magnet has injected new vigor and vitality into the field of rare earth technology. It is known as the "king of permanent magnet", which is widely used in electronics, machinery and other industries. The development of alpha magnetic spectrometer indicates that the magnetic properties of nd-fe-boron magnets can reach the world-class level. Neodymium is also used in nonferrous materials. It is widely used as aerospace materials to add 1.5 ~ 2.5% neodymium to magnesium or aluminum alloy, which can improve the high temperature performance, air tightness and corrosion resistance of alloys.

In addition, neodymium-doped yttrium aluminum garnet generates a short wave laser beam, which is widely used in the industry for welding and cutting of thin materials with thickness of 10mm. In medical treatment, the use of neodymium yttrium aluminum garnet laser instead of a scalpel is used to remove or disinfect wounds. Neodymium is also used in the coloring of glass and ceramic materials and additives in rubber products. With the development of science and technology, development and extension of rare earth science and technology field, neodymium elements will have a wider use space. Promethium (Pm)
In 1947, the mariinsky (J.A.M arinsky), glen tannin (L.E.G lendenin) and collier (C.E.C oryell) from the atomic reactor used successfully isolated in the uranium fuel element 61, with the name of god in Greek mythology (Prometheus) named Prometheus Promethium (Promethium).

Promethium is the artificial radioactive element produced by the nuclear reactor. The main purpose of promethium is (1) to be a heat source. It provides auxiliary energy for vacuum detection and artificial satellites. (2) Pm147 emits low-energy beta rays for the manufacture of promethium cells. As a missile guidance instrument and a power source for clocks and watches. This kind of battery is small and can be used continuously for years. In addition, promethium is also used in portable X-ray apparatus, fabrication of phosphor powder, thickness of measurement, and beacon light.

Samarium
In 1879, the new rare earth elements were found in the "praseodymium" obtained from niobium, and named samarium according to its name.

Samarium is a light yellow and is the raw material of the samarium cobalt permanent magnet, which is the first rare earth magnet for industrial application. This permanent magnet has SmCo5 series and Sm2Co17. In the early 1970s, SmCo5 was invented and Sm2Co17 was invented. Now it is the latter's demand. The purity of the samarium oxide used in the samarium cobalt magnet is not too high, and it mainly USES about 95% of the products in terms of cost.

In addition, samarium oxide is used for ceramic capacitors and catalysts. In addition, samarium has a nuclear nature, which can be used as the structural material of the nuclear reactor, the screen materials and the control materials, so that the nuclear fission generates a huge amount of energy to be safely utilized.

Europium
In 1901, Eugene-Antole Demarcay discovered the new element from "samarium", which was named Europium. This is probably named after Europe. Europium is used mostly in phosphors. Eu3+ for red phosphor activator, Eu2+ for blue phosphor.

Now Y2O2S:Eu3+ is the best fluorescent powder for luminous efficiency, coating stability and recovery cost. Combined with improvements in the improvement of luminous efficiency and contrast, it is widely used. Europium has also been used to activate fluorescent phosphors in new X-ray medical diagnostic systems.

Europium is also used in the manufacture of colored lenses and optical filters for magnetic bubble storage devices, which can also be used in the control materials, shielding materials and structural materials of atomic reactors.

Gadolinium

In 1880, Swiss Mali Wagner g (G.d e Marignac) will "samarium" separated into two elements, one of them by cable was confirmed by samarium element, another element to get wave according to the research of BaoDe lai confirmed that in 1886, Mali Wagner g to commemorate the discoverer of the element yttrium research p ioneer of rare earths added Dutch chemist Lin (Gado Linium), named this new element gadolinium.

Gadolinium plays an important role in modern technological innovation. Its main use is:

(1) its water-soluble paramagnetic complex can improve the human's nuclear magnetic resonance (NMR) imaging signal in medical treatment.

(2) the sulfur oxide can be used as a substrate for the special luminance of the oscillograph tube and X-ray fluorescence screen.

(3) gadolinium in gadolinium gallium gallium is an ideal single substrate for magnetic bubble memory memory.

(4) it can be used as a solid-state magnetic refrigerating medium in the absence of the Camot cycle limitation.

(5) used as a chain reaction level inhibitor to control nuclear power plants to ensure the safety of nuclear reactions.

(6) used as an additive for samarium cobalt magnets to ensure that the performance does not vary with the temperature. In addition, gadolinium is used with lanthanum to help change the glass area and improve the thermal stability of the glass. Gadolinium is also used to make capacitors, X-ray sensitized screens.

In the world are currently working to develop gadolinium alloys in magnetic refrigeration applications, has been a breakthrough, at room temperature using superconducting magnets, metal gadolinium, or its alloys for refrigerating medium magnetic refrigerator has been available.

Terbium
In 1843, Karl g.osander of Sweden discovered Terbium (Terbium) by studying yttrium soil. The application of terbium mainly involves high technology field, which is a highly technical and knowledge-intensive cutting-edge project, which is also a project with significant economic benefit, and has an attractive prospect for development. Main application areas are:

(1) the phosphors used in the activation of the green tricolor phosphors powder agent, such as terbium activated phosphate matrix, terbium cerium activate a silicate substrate, terbium magnesium aluminate matrix, all the green light under the excited state.

(2) the magnetic optical storage materials, in recent years the department of terbium magneto-optic material has reached the scale of mass production, developed with Tb - Fe amorphous thin film magnetic optical discs, computer storage devices, storage capacity 10 ~ 15 times.

(3) magnetic light glass, the Faraday rotatory glass containing terbium is the key material for the widely used rotator, isolator and annular apparatus in laser technology. Especially terbium, dysprosium ferromagnetic striction alloy (TerFenol) is developed, but also opened up a new use of terbium, TerFenol is a new kind of material, in the 70 s found that half of the alloy composition of terbium and dysprosium, sometimes join holmium, the rest of the iron, the alloy by the Iowa Ames laboratory developed first, when TerFenol placed in a magnetic field, its size changes than the average change of magnetic materials, and this change can make some precision mechanical movement. Start is mainly used in sonar, terbium, dysprosium iron currently has been widely used in various fields, from the fuel injection system, fluid control valve, micro mechanical actuator, a space telescope to locate the regulator and the regulator in the fields of airplane wings.

Dysprosium
In 1886, the Frenchman boyce baudelle succeeded in separating holmium into two elements, one still known as holmium, while the other was named dysprosium, which was "hard to get" from holmium. Dysprosium currently in many high technology plays a more and more important role, is the primary purpose of dysprosium

(1) used as additive of ndfeb is a permanent magnet, in this kind of magnets to add 2 ~ 3% of dysprosium, the coercive force can be improved, the demand for dysprosium is not big, but with the increase of demand ndfeb magnet, it becomes necessary to add elements, grade must be about 95 ~ 99.9%, the demand is increasing rapidly.

Dysprosium (2) as an activator phosphors, trivalent dysprosium is a kind of promising single active ion luminescence center tricolor luminous material, it is mainly composed of two emission band, a yellow light emission, another is blue light emission, mixed dysprosium luminescent material can be used as tricolor phosphors.

(3) dysprosium is a necessary metal raw material for the preparation of Terfenol, a large magnetostrictive alloy, which enables the precise movement of some mechanical movements.

(4) dysprosium metal can be used as magnetooptic storage material with high recording speed and reading sensitivity.

(5) is used for the preparation of dysprosium lamp, used in dysprosium lamp working substance is dysprosium iodide, this kind of lamps and lanterns has brightness, good color, high color temperature, small size, stable arc, etc, have been used for film, printing and other lighting light source.

(6) because dysprosium has the characteristics of neutron capture and truncated area, the neutron energy spectrum or neutron absorber is used in the atomic energy industry.

(7) Dy3Al5O12 can also be used as magnetic working substance for magnetic refrigeration. With the development of science and technology, the application of dysprosium will be continuously expanded and extended.

Holmium
In the 19th century, because of the discovery of spectrum analysis and published the periodic table, plus the progress of electrochemical separation process of rare earth elements, more promote the discovery of new rare earth elements. In 1879, the Swedish man cliff discovered holmium and named it holmium in the Swedish capital of Stockholm.

Holmium applications at present has yet to be further development, the dosage is not very big, recently, baotou rare earth research institute USES high temperature and high vacuum distillation purification technology, developed the high purity of rare earth impurity content is very low metal holmium Ho/Σ RE > 99.9%. At present the main use of holmium: used as metal halogen lamp additives, metal halide lamp is a gas discharge lamp, it is developed on the basis of high pressure mercury lamp, its characteristic is in the light bulb filled with a variety of different rare earth halide.

At present, rare earth iodide is mainly used to emit different spectral lines in the gas discharge. The working substance used in the holmium lamp is iodized holmium, which can obtain higher metal atomic concentration in the arc zone, thus greatly improving the radiation efficiency.

(2) holmium can be used as an additive in yttrium iron or yttrium aluminum garnet;

(3) yttrium aluminium garnet (Ho: YAG) with holmium is capable of emitting 2 mu m laser, and the human body tissue has high absorption rate of 2 mu m laser, which is almost 3 orders of magnitude higher than Hd: YAG. Therefore, using Ho:YAG laser can not only improve the efficiency and precision of operation, but also reduce the area of thermal damage. Holmium crystals produce free beam can eliminate fat, won't produce too much heat, thus reduce the thermal damage to healthy tissue, reported to the United States with holmium laser treatment of glaucoma, can reduce the pain of the patients. The level of 2 mu m laser crystal has reached the international level and the laser crystal should be developed vigorously.

(4) in the magnetostrictive alloy terfenol-d, a small amount of holmium can also be added, thus reducing the outer field required for the saturation magnetization of the alloy. (5) in addition, the optical fiber with holmium can be used to make fiber lasers, optical fiber amplifiers, fiber optic sensors and other optical communication devices to play a more important role in the rapid development of optical fiber communication.

Erbium
In 1843, the Erbium was discovered by mosander of Sweden. Erbium optical properties is very outstanding, has always been a matter of concern: (1) the Er3 + light emission at 1550 nm with special significance, because the wavelength is just the m inimum loss in optical fiber communication optical fiber, erbium ions (Er3 +) by the wavelength of 980 nm, 1480 nm light excitation, 4 i15/2 from the ground state transition to upper state 4 i13/2, when in the upper state Er3 + to transition back to the ground state when emit 1550 nm wavelength of light, quartz optical fiber can transmit different wavelengths of light, but different light failure rate is different, in the light of 1550 nm band quartz optical fiber transmission attenuation time m inimum (0.15 db/km), almost to the lower limit of attenuation rate.

As a result, optical fiber communication at 1550nm signals light at least. So, if the appropriate concentration of erbium doped suitable matrix, can according to the principle of laser effect, loss in the amplifier can compensate the communication system, so the need to enlarge the wavelength of 1550 nm light signals in the telecommunications network, erbium-doped fiber amplifier is indispensable optical device, the erbium-doped silica fiber amplifier has been commercialized.

To avoid unwanted absorption, the doped amounts of erbium in the fiber are reported to be tens to hundreds of parts per million. The rapid development of optical fiber communication will open up a new field of erbium. (2) the other erbium laser crystal and its output of 1730 nm and 1550 nm laser is safe for people eyes, atmospheric transmission performance is good, the smoke of the battlefield penetration ability is stronger, the secrecy good, not easy detection by enemy, illuminate large quantities of military targets, has made it safe for military use portable laser range finder. (3) Er3+ can be added to glass to be made of rare earth glass laser material, which is the largest output pulse energy and the highest output of solid laser material. (4) Er3+ can also make the activation ion of laser material on rare earth. (5) erbium can also be used for the discoloration and coloring of glass and crystal glass.

Thulium
The Thulium was discovered by Clifford in Sweden in 1879 and was named Thulium in the old name of Scandinavia.
Thulium has the following several aspects:

(1) the main purpose of thulium ray source used as medical portable X-ray machine, thulium can after irradiation in the nuclear reactor to produce a X-ray of isotope that can be used to manufacture portable blood irradiation on the instrument, the radiometer can make thulium - 169 is the role of high neutron beam into thulium - 170, emit X-ray irradiation blood and decreased white blood cells, and it is these white blood cells cause of organ transplant rejection, thereby reducing the early rejection of organ.

(2) thulium element can also be applied to clinical diagnosis and treatment of tumor, because it to tumor tissues with high affinity, heavy rare earth greater than light rare earth affinity, especially with the affinity of the thulium element is the largest.

(3) thulium in X-ray intensifying screen do activator in the fluorescent powder LaOBr: Br (blue), to enhance the optical sensitivity, and thus reduce the X-ray radiation and harm of people, compared with calcium tungstate intensifying screen before can reduce X ray dose by 50%, in the medical application has the important practical significance.

(4) thulium can also be used as an additive in new lighting source metal halide lamps.

(5) Tm3+ is added to glass to be made into a rare earth glass laser material, which is the most current output pulse volume and the highest output of solid laser material. Tm3+ can also be used to convert laser material to activate ions.

Ytterbium
In 1878, a new rare earth element was found in "erbium" by Jean Charles and g.d. Marignac, which was named Ytterbium by Ytterby.

The main purpose of ytterbium is (1) thermal shielding coating material. Ytterbium can obviously improve the corrosion resistance of the electrodeposited zinc layer, and the ytterbium coating ratio is smaller than that of ytterbium coating, which is uniform and dense.

(2) magnetostrictive materials. This material has the properties of supermagnetic scalability, which is the expansion of the magnetic field. The alloy is mainly composed of ytterbium/ferrite alloy and dysprosium/ferrite alloy and is added to a certain proportion of manganese to produce supermagnetic scalability.

(3) the ytterbium component for the determination of pressure is proved to be sensitive in the calibrated pressure range and a new approach to the application of pressure determination for ytterbium.

(4) the resin base fillings of the molars are used to replace the commonly used silver amalgam alloys.

(5) Japanese scholars have successfully completed the preparation of a waveguide laser with ytterbium-doped gadolinium gallium garnet embedded. The completion of this work is of great significance to the further development of laser technology. In addition, ytterbium is also used in fluorescent powder activators, radio ceramics, electronic computer memory components (magnetic bubble) additives, glass fiber aid and optical glass additives.

Lutetium
In 1907 Wells Bach and especially bain (G.U rbain) respectively, with different separation methods from the ytterbium, and discovered a new element in the Wells Bach named the elements of the Cp (Cassiopeium), especially according to the old name of Paris bain lutece named Lu (Lutetium). It turns out that Cp and Lu are the same elements, and that is called lutetium.

The main purpose of lutetium is (1) to make some special alloys. For example, the aluminium alloy can be used for neutron activation analysis. (2) stable lutetium is catalyzed in petroleum cracking, alkylation, h ydrogenation and polymerization. (3) adding elements of yttrium iron or yttrium aluminum garnet to improve some performance. (4) the raw material of the magnetic bubble storage device. (5) a compound function four aluminium borate crystals lutetium doped yttrium neodymium, belongs to the salt solution cooling technology of crystal growth, the experiment proved that the mixed lutetium NYAB crystals in the optical homogeneity and laser performance is better than that of NYAB crystal. (6) it has been found that lutetium has potential USES in electrochromic and low-dimensional molecular semiconductors. In addition, lutetium is also used in energy battery technology and fluorescent powder activators. Yttrium (Y)

In 1788, a to study chemistry, and mineralogy, collect ore amateur Sweden officer Carl areni uz (Karl Arrhenius) in Stockholm kuyt will village outside the bay (Ytterby), found the appearance as black as coal tar and minerals, according to the local place name named kuyt will mine (Ytterbite). In 1794, the Finnish chemist John gardoin analyzed the eite sample. It found that in addition to beryllium, silica, iron oxide, it also contained about 38% of the unknown element oxide date "new soil". In 1797, Swedish chemist Anders Gustaf Ekeberg identified the "new soil" named Yttria (the meaning of Yttria, a yttrium oxide).

Yttrium is a widely used metal, mainly used in: (1) additives for steel and non-ferrous alloys. FeCr alloys usually contain between 0.5%-4% yttrium and yttrium enhances the antioxidant and malleability of these stainless steel. After adding a moderate amount of polyyttrium mixed rare earth to the MB26 alloy, the comprehensive properties of the alloy have been significantly improved, which can be used to replace the strong aluminum alloy in the components of the aircraft. In al-zr alloy, a small amount of yttrium rare earth can be added to improve the conductivity of the alloy. The alloy has been used in most domestic wire plants. The addition of yttrium in copper alloy enhances electrical conductivity and mechanical strength.

(2) nitride ceramic materials containing yttrium 6% and aluminum 2% are used to develop engine parts.

(3) the large components are drilled, machined and welded with the power of the 400w yttrium aluminum garnet laser beam.

(4) electron microscope fluorescent screen composed of the y-al garnet single crystal sheet, high luminance, low absorption of scattered light, high resistance to high temperature and abrasion resistance of mechanical wear.

(5) the high yttrium structure alloy with yttrium (yttrium) 90% can be used in aviation and other occasions requiring low density and high melting point.

(6) the high temperature proton conduction material of yttrium SrZrO3, which is currently being closely watched, is of great significance for the production of fuel cells, electrolytic pools and gas-sensitive components requiring high solubility of h ydrogen. In addition, yttrium is also used to resist high temperature spraying materials, the diluent of nuclear reactor fuel, the additive of permanent magnetic materials and inhalation in the electronics industry.

Scandium
In 1879, Swedish chemistry professor nelson (L.F.N ilson, 1840~ 1899) and Clive (P.T.C. leve, 1840~ 1905) found a new element in the rare mineral silicon beryllium and black gold mines. They named the element Scandium, the "boron" element that mendeleev predicted. Their findings reprove the correctness of the periodic law and mendeleev's vision.
Scandium compared with yttrium and lanthanide, due to the ionic radius small, hydroxide alkaline is particularly weak, therefore, scandium and rare earth elements together, with ammonia (or extremely dilute alkali treatment, scandium will be the first to precipitate, so the application of the fractional precipitation technique can be more easily to separate it from the rare earth elements. The other method is to use the separation of nitrite splitting, which is the most easy to decompose, so that the separation can be achieved.

The metal scandium was made by electrolysis method, ScCl3, KCl and LiCl were fused in the process of refining, and the molten zinc was cathode electrolysis, so that the scandium was precipitated out of the zinc electrode, and then the zinc was steamed to get the metal scandium. In addition, it is easy to recover scandium when processing ore to produce uranium, thorium and lanthanides. Scandium of the integrated recovery of tungsten and tin ore is also an important source of scandium.

Scandium is mainly in 3 valence states in the compound, easily oxidized into Sc2O3 in air and lose the metallic luster to dull gray.

Scandium can release h ydrogen from hot water and is also soluble in acid, which is a strong reducing agent.
Scandium oxide and hydroxide are only alkaline, but their salt ash can hardly h ydrolyze. Scandium chloride is white crystal, easily soluble in water and can be dissolved in the air.

In the metallurgical industry, scandium is often used to make alloys (alloy additives) to improve the strength, hardness and heat and performance of alloys. For example, adding a small amount of scandium to iron water can significantly improve the performance of cast iron. A small amount of scandium is added to aluminum to improve its strength and heat resistance.

In the electronic industry, scandium can be used for a variety of semiconductor devices, such as scandium sulfite in the semiconductor has attracted the attention of both at home and abroad, the application of scandium ferrite in computer magnetic core is promising.

In the chemical industry, it is used as an effective catalyst for producing ethylene and producing chlorine with waste hydrochloric acid by using scandium compound as alcohol deh ydrogenation and dehydrating agent.
In the glass industry, special glass containing scandium can be made.

In the industry of electric light source, scandium and sodium are made of scandium and sodium, which have the advantages of high efficiency and bright color.

In nature, scandium is in the form of 45Sc, and the scandium also has 9 radioactive isotopes, 40 ~ 44Sc and 46 ~ 49Sc. 46Sc, as tracer, has been used in chemical, metallurgy and oceanography. In medicine, there are also studies using 46Sc to treat cancer. The nature and use of scandium.