While reading an article, which mentioned nickel’s availability in the Earth’s inner core, a question about nickel’s magnetic property popped into my head. So I thought of doing a quick Google search. And after going through different facts, I jolted down the results. In this article, I will explain to you guys those facts and help you dive deep into “Nickel’s World”. So let’s find out about the magnetic properties of nickel in a detailed way!
So, is nickel magnetic? Nickel (Ni) is ferromagnetic in nature, because of the parallel alignment of its 2 unpaired electrons or ‘spins’ in presence of an external magnetic field. Nickel holds its magnetic property even in absence of any magnetic field, which gives permanent magnetization to it.
Nickel exists as a silvery-white lustrous metal with a tinge of gold. It belongs to the group of transition metals with atomic number 28, and atomic weight 58.69 u.
It is the 5th most abundant element present on earth. Nickel is among the four ferromagnets which are used to make Alnico magnets.
There is a long history of Nickel being used as a coin. The US five-cent piece is composed of 25% nickel and 75% copper.
Naturally, nickel has 5 stable isotopes.
They are:- Nickel-58 (68.27%), Nickel-60 (26.10%), Nickel-61 (1.13%), Nickel-62 (3.59%) and Nickel-64 (0.94%).
Now let’s move on to the reasons for nickel’s ferromagnetism in a detailed way.
Why is Nickel Ferromagnetic?
According to the electronic configuration; [Ar] 3d8 4s2, nickel has 2 unpaired electrons in the d orbital.
These two unpaired electrons align parallelly in the presence of an external magnetic field and remain aligned even after the magnetic field is removed. This is the main reason for the ferromagnetic nature of Ni.
The above-attached image shows the filling of electrons in different orbitals for nickel and we can clearly point out 2 unpaired electrons in the d orbital.
We know paramagnetism, ferromagnetism or diamagnetism depends on unpaired electrons. The presence of unpaired electrons indicates paramagnetism and ferromagnetism as well.
Whereas the presence of paired electrons indicates diamagnetism.
Now permanent magnets are those which can remain magnetized even after removal of the external magnetic field. Nickel falls under this category.
Magnetic domains are the tiny pockets containing magnetic dipoles. Every magnetic material is made up of these domains.
The magnetic dipoles inside these domains align parallelly in a single direction and are the main reason for the strong magnetic field of Ni.
The alignment remains even after the removal of the external magnetic field. This tendency of “remembering the magnetic history” is called hysteresis.
This concept can be visually understood from the attached image below, where domains in the case of iron are shown. Nickel behaves similarly that to iron.
The domains of ferromagnetic materials have a high degree of magnetization but these domains are randomly oriented in absence of an external magnetic field.
So any slight presence of any external magnetic field can align the domains giving rise to strong magnetization.
Magnetic Susceptibility of Nickel
Magnetic susceptibility can be defined as the degree to which a material can be magnetized in an external magnetic field. In simple words, we can say, the degree to which a material is attracted to a magnet.
Magnetic susceptibility is very high for nickel due to the parallel alignment of magnetic dipoles.
But things change after Curie’s temperature. Thermal agitation above curie temperature destroys the parallel alignment of the dipoles and they orient randomly once again.
For this reason, above Curie temperature nickel loses its ferromagnetic property and becomes paramagnetic, just like iron. For a nickel, Curie’s temperature is 355°C (671°F).
The graph shows the change in magnetic susceptibility for paramagnets and ferromagnets. The change after the curie point for ferromagnetic materials is very clear from the graph.
Is Nickel more magnetic than iron?
Nickel can remain in its fcc structure up to very large pressures. Its magnetic moments are smaller but more strong and healthy than those of iron.
If we talk about magnetic moments, which tells us about the magnetic strength of a material, we can see it’s quite high for nickel but when compared to iron, it is smaller.
As iron has 4 unpaired electrons while nickel has only 2. The formula for the magnetic moment is attached below.
Nickel have different oxidation states like Ni, Ni+, Ni3+, Ni2+, among which Ni2+ is most common.
Some exotic oxidation states like Ni1-, Ni2-, Ni4+ are also produced and studied thoroughly.
The bulk of the nickel is mined from 2 types of ore deposits. First is laterite and 2nd is magmatic sulfide deposits.
Apart from nickel, cobalt and gadolinium are also similar metals that are ferromagnetic at normal room temperature.
The magnetic moment of cobalt is around 1.6–1.7 and that of gadolinium is 7.29.
Are complexes of Nickel magnetic?
Magnetic moments for Ni(II) complexes are 3.30, 3.35, and 2.76 BM at room temperature.
For a nickel, be it high spin complex or low spin complex, unpaired electrons present will be 2. So unlike iron, its magnetic moment does not depend on the type of ligand.
Nickel is a good conductor like all metal because it permits the movement of electrons through them. Also malleable and ductile with high thermal and electrical conductivity.
Nickel is an excellent alloying agent. It is used often in the fire assay for collecting platinum group elements (PGE).
Nickel is undoubtedly capable of collecting all 6 PGE elements from ores. This metal along with its alloy is often used as catalysts for hydrogenation reactions.
History of Nickel
The use of nickel unintentionally started back in 3500 BCE but was often mistaken with ore of silver. Originally the only source of nickel was the rare Kupfernickel.
In the year 1824, nickel was produced as a byproduct of cobalt-blue production. In 1848, the first large-scale smelting of nickel began in Norway.
The huge production of nickel is used in the following percentages:-
- 68% in stainless steel
- 10% in nonferrous alloy
- 27% for engineering purpose
- 10% for building construction
- 14% for tubular products
- 20% for metal goods
- 14% for transport
- 9% in electroplating
- 7% in alloy steel
- 3% in foundries
- 4% in other uses including batteries
Because of its resistance to corrosion, nickel was occasionally used as a substitute for decorative silver.
Some of the usages of nickel include coinage, rechargeable batteries, Alnico magnets, stainless steel, electric guitar strings, microphone capsules, plumbing fixtures.
The green tint on glasses comes from this nickel plating.
The largest reserves of nickel, about 46% of the world’s total count is in Indonesia and Australia.
Nickel is extracted from ore by roasting and reduction methods which give a 75% purity. This 75% pure nickel can be used in different stainless steel applications.
So we came to the conclusion that Nickel is a ferromagnetic substance. The main reason for its ferromagnetism is the presence of 2 unpaired electrons. The electrons align parallelly in presence of an external magnetic field. Nickel holds its magnetic property even after removal of the external magnetic field which makes it a permanent magnet.
So, guys, I tried to make you understand magnetism in nickel in detail. Let me know through your valuable comments if you have any queries related to it.