Gadolinium

With over 13 natural isotopes and known for its wide range of applications today, Gadolinium is the 66th element in the Periodic Table. Denoted as Gd, this element is classified under the section of lanthanides. Malleability, solubility, ductility, and high thermal stability are all the notable features of this chemical element. The important, booming fields of technology and medical sciences, prefer Gadolinium over others considering its chemical and physical properties. Let us hence learn about the important basics of Gadolinium’s properties, applications and other interesting facts on the go.


A Quick Note of What Gadolinium is

The discovery of Gadolinium (The element’s symbol is Gd) dates back to 1880. The Swiss chemist ‘Jean Charles Galissard de Marignac’ found Gadolinium by using the method of spectroscopic line detection over the compound Gadolinia. Following which, the 1st isolation was a success in 1886, by the French chemist ‘Paul Émile Lecoq de Boisbaudran’ by separating this element Gadolinium from “Gadolinia ''. 


In the absence of an oxidized state, Gadolinium is a silvery-white lanthanide metal, present in the 66th position of the f-block and the 6th row of the Periodic Table. The compound’s atomic number is 64. Nuclear reactors, radiography, electronic device production, metallurgy and many other applications can be listed for using Gadolinium in the areas of technology, arts and science, engineering, medicine, etc.


The Notable Physical Properties of Gadolinium

  • Solid structure at  20°C STP (Standard Conditions for Temperature and Pressure).

  • Position of Gadolinium in the Periodic Table is 66, f-Block, 6th row, put under the category of lanthanides. 

  • Toxicity is said to be lower but triggers issues such as skin and eye irritation for human beings. No prominent effect over animals and plants due to Gadolinium. 

  • Soft and silvery-white bright metal.

  • The element is named with its primary mineral, Gadolinite.

  • Gadolinium is both ductile and malleable. 

  • [GAD-ə-LIN-ee-əm] is the pronunciation for Gadolinium. 

  • The element is found in the earth’s crust at the range of 5.2 parts per million.

  • One of the rarely observed metals on the earth.

  • HCP (Hexagonal Close Packing) is the crystal structure. 

  • Has good resistance to high-temperature conditions. 

  • Has 13 naturally-derived isotopes and 27-synthetic isotopes. 

  • Paramagnetic at room temperature and turns into a ferromagnetic substance at colder conditions (estimated to be above 20°C). 

  • Gadolinium is a form of Primordial isotope. 

  • When added together with sulfur, boron, selenium, nitrogen, carbon, arsenic, phosphorus, and silicon, the element Gadolinium will create binary compounds as a result of its chemical reaction. 

  • Highest thermal stability is noted with the isotope 157 Gd.


Points Covering the Chemical Properties of Gadolinium

  • Molecular Weight of Gadolinium is 157.25 g/mol-1.

  • The atomic number is 64.

  • The count of electrons per each shell is 2, 8, 18, 25, 9, and 2.

  • Boiling point is 3273°C at 5923°F and 3546 K

  • 7.90 is the Density (g / cm−3).

  • [Xe] 4f7 5d1 6s2 is the electronic configuration of Gadolinium. 

  • Trivalent bond formation during its compound state.

  • Both the exact and monoisotopic mass value is 157.92411 g/mol.

  • The presence of 1 Heavy Atom counted. 

  • Estimated Molar Heat Capacity is 37.03 J/(mol·K).

  • Highly reactive with other dilute acid forms.

  • There is 1 Covalently-Bonded Unit.

  • 17°C is the estimated value for the Curie Point. 

  • 1313°C is the melting point of Gadolinium at 2395°F, 1586 K.

  • Gadolinium is a Canonicalized element. 

  • Unreactive with oxygen but in the presence of moist air, the element will tarnish and create a layer of white oxide, which is gadolinium(III) oxide (Gd2O3), for restricting further oxidation. 


Occurrence and Existence of Gadolinium and its Isotopes

154Gd, 155Gd, 156Gd, 157Gd, 158Gd, and 160Gd are the 6 major isotopes of Gadolinium. There are about 29 different radioactive isotopes for Gd, out of which, 152Gd is said to be the naturally-occurring isotope of Gd that possesses high stability. Note that the primary mode of decaying in Gadolinium is beta decay at conditions of higher atomic mass and the resulting product is an isotope of terbium. 


Even though the exact measure of producing Gadolinium varies annually, it is anyhow estimated to be around 400 tonnes per year. The metal is not present in the natural environment owing to its high reactivity. 


The lanthanide Gadolinium is noted to be found in specific mineral oxides such as bastnäsite and monazite. Even the mineral Gadolinite has only a sizable quantity of Gadolinium with it. ‘Lepersonnite-(Gd)’ is one of the key minerals known to be closely associated with Gadolinium and is extremely rare for existence. 


India, Sri Lanka, the United States of America, China, and Brazil are some of the notable countries, where 1 million is the estimated exceed of reserved value for Gadolinium. 


Real-Life Uses of Gadolinium with Examples

  • Video recorders and other electronic devices are produced by making use of the alloys of Gadolinium.

  • Gadolinium is used as a Dopant for producing fuel cells, as in the case of cerium oxide, which is one of the optimal and cost-effective methods. 

  • In the case of a  CANDU reactor type, the isotope 157Gd is useful to impact in conditions of emergency shutting-down of nuclear programmes. Moreover, the same element is preferred as a burnable poison for nuclear marine propulsion.  

  • To imitate diamond stones and jewellery, workers tend to use the Gadolinium Gallium Garnet (GGG, Gd3Ga5O12). 

  • Colour Television Gadgets prefer Gadolinium in the form of Phosphorus and even to manufacture microwave-related appliances. Similarly, this change is noted in the case of x-ray machines, where Gadolinium acts as suspension for a polymer matrix in the region of detection. 

  • Since Gadolinium has good resistance to high temperatures, the lanthanide is used in the making of other high-temperature gadgets. 

  • Targeting the tumour cells during a neutron therapy is possible from using the isotope 157Gd. This applies even to nuclear reactors and neutron radiography techniques. 

  • Magnetic Resonance Imaging (MRI) makes use of Gadolinium Contrast, owing to its paramagnetic ions where it enhances the nuclear relaxation rates.


Conclusion

Gadolinium is a silver-white coloured lanthanide metal, with atomic number 64 and present in the f-block’s 66th position in the Periodic Table. The element was discovered by a Swiss Chemist in 1880 and was isolated by a French Chemist in 1886. Gadolinium denoted as Gd has multiple radioactive isotopes and a vast majority of them are not found in the natural atmosphere due to its high reactivity. This compound is a solid structure with HCP formation at STP and has high resistive power to extremely heated conditions. Domains such as electronic production, chemical oxidation, diamond imitation, nuclear power plants, fuel cell generation, are some of the common instances where Gadolinium is preferred at different stages of production and manufacturing.

FAQ (Frequently Asked Questions)

1. What is the Biological Role of Gadolinium?

Apart from being a useful resource in the file of biomedicine, Gadolinium has no proper biological role. Moreover, MRI Gadolinium Contrast agents are possible only because of Gd³⁺.

2. Mention the Problem that may Arise due to Using Gadolinium Contrast in MRI.

By using Gadolinium Contrast in MRI, there is this risk of getting a rare but serious medical illness called Nephrogenic Fibrosing Dermopathy or Nephrogenic Systemic Fibrosis (NSF). This is a condition similar to scleroderma and scleromyxedema and arises due to prolonged exposure to contrast MRI that uses Gadolinium. The adversity in reaction or result of using Gadolinium Contrast varies based on the hypersensitivity of the patient and the duration of exposure (acute or chronic).

3. Briefly explain the method of producing Gadolinium with the 2 mineral oxides monazite and bastnäsite.

By using acids such as Sulfuric and  Hydrochloric liquids, the oxide minerals monazite and bastnäsite are converted into soluble sulfates and chlorides. With a pH value of 3 to 4, caustic soda is used here for partial neutralization of the acidic filtrates. Now, the solution is treated with ammonium oxalate and is transformed into soluble oxalates and then again changed into oxides by heating the mixture. Dissolve the oxide into nitric acid and treat it with magnesium nitrate, the salts are processed using the ion-exchange method and thus the resulting salts are Samarium, Europium, and Gadolinium. And then finally, in the argon atmosphere, Gadolinium is separated by heating the component with calcium.

4. Give the Young’s, Shear’s, and Bulk Modulus values for Gadolinium.

The Young’s Modulus value is 54.8 GP with Shear value as 21.8 GPa. Gadolinium’s Bulk Modulus rate is 37.9 GPa.

5. Are there any disorders or medical conditions associated with using Gadolinium?

Yes. Medical disorders such as Nephrogenic Fibrosing Dermopathy, Renal Insufficiency, Acute Kidney Injury, and other Kidney-related injuries are possible as well.