Material Which Changes Its Magnetic Properties Under Mechanical Strain

The world is depleting of resources for generation of electricity. Engineers are moving from coal based electricity to the solar panel based electricity. The piezoelectric materials also generates electricity by tapping them i.e compressing or stretching. This free-form type of electricity is widely used in malls and places where lots of people walk.

Figure 1- Piezoelectric material used in Cigarrette lighters

This material hasn’t gain much more popularity than every other free-form of electricity. Since, it requires compressing and stretching, it requires man-power.
Researchers are constantly finding new ways in the field of technology. Recently a group of researchers have found a new material which is similar to piezoelectric material. This newly found material when stretched or put under mechanical strain change it’s magnetic properties. Thus, this material is termed as “piezomagnetic” material. 
The researchers were trying to study about the material using NMR imaging to see whether they can change the material into rectangular configuration when applied a mechanical force.
This material goes into a phase transition before it acts as a superconductor. It has a square configuration which goes into rectangular configuration after applying mechanical strain. This BaFe2As2 is also called as “nematic” crystal.
The researchers’ team is led by Nicholas Curro, professor of physics at UC Davis and senior author of a paper on the discovery published March 13 in the journal Nature Communications.
They found that when barium-iron-arsenic compound mixed with small quantities of other elements at about 25 Kelvin temperature acts as a superconductor. This material can be stretched into cables and wires at cold temperatures.
“Piezomagnetic materials are rarely found in nature, as far as I’m aware”, Curro said.
The crystal can change the direction of magnetism and can come out of plane under mechanical strain.
The crystal also acts as an antiferromagnet. This is because the spins of atoms point in alternating opposite directions. This magnetic spins can change its direction under stress.
Currently, this group of researchers have no theory to explain the results achieved. They are finding other materials which can exhibit the same behaviour under mechanical strain. The experiments related to other similar materials are currently performed at room temperatures and not in cold temperatures.
This material can be used in applications such as aircraft components and mining.

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