Magnetoresistance of MXene to predict distribution of molecules

The magnetoresistance property of MXene has been utilised by researchers to develop a way to predict the distribution of molecules on the surface.

MXene is a two-dimensional nanomaterial with alternating layers of metal and carbon that exhibits strong electrical conductivity and may be mixed with different metal compounds. As a result, it can be used in a variety of sectors, including semiconductors, electronic devices, and sensors.

With the use of this method, it is able to quickly determine the molecular distribution of MXene, allowing for quality control throughout production and, ultimately, paving the way for hitherto impractical mass production.

Knowing the type and quantity of molecules covered on the surface of MXene is crucial for its effective use; if the molecules are fluorine, the material's electrical conductivity and effectiveness as an electromagnetic wave shield both diminish.

However, even with a high-performance electron microscope, it takes several days to analyse the molecules on the surface because it is just 1 nm (nanometer - billionth of a metre) thick, making mass production up to now impractical.

The research team developed a two-dimensional material property prediction program based on the idea that electrical conductivity or magnetic properties change depending on the molecules attached to the surface.

As a result, they calculated the magnetic transport properties of MXene and succeeded in analyzing the type and amount of molecules adsorbed on the surface of MXene at atmospheric pressure and room temperature without any additional devices.

By analyzing the surface of the MXene with the developed property prediction program, it was predicted that the Hall scattering factor, which affects magnetic transport, changes dramatically depending on the type of surface molecules.

The Hall Scattering Factor is a physical constant that describes the charge-carrying properties of semiconductor materials, and the team found that even when the same MXene was prepared, the Hall Scattering Factor had a value of 2.49, the highest for fluorine, 0.5 for oxygen, and 1 for hydroxide, allowing them to analyze the distribution of the molecules.

The Hall scattering coefficient has different applications based on the value of 1. If the value is lower than 1, it can be applied to high-performance transistors, high-frequency generators, high-efficiency sensors, and photodetectors, and if the value is higher than 1, it can be applied to thermoelectric materials and magnetic sensors.

Considering that the size of the maxin is a few nanometers or less, the size of the applicable device and the amount of power required can be dramatically reduced.

"Unlike previous studies that focused on the production and properties of pure MXene, this study is significant in that it provides a new method for to easily classify manufactured MXene," said Seung-Cheol Lee, director of IKIST.

"By combining this result with experimental studies, we expect to be able to control the production process of MXene, which will be used to mass produce MXene with uniform quality."