2D crystals developed by physicists offer potential for improved electronics.

A group of specialists, driven by College of Texas at Dallas researchers, has fostered another strategy to develop uncommonly huge, great precious stones that could end up being useful to make progressed gadgets, for example, spintronic and attractive optoelectronic gadgets, a reality.

Extremely slender layers — only a couple of iotas thick — can be peeled effectively from the mass of precious stones. These two-dimensional layers are interesting for use in devices with stacked layers of different materials because they have surprising magnetic properties and are very stable in air at room temperature.

The solid-vapor synthesis method for growing chromium sulfide bromide crystals, which are typically produced using the chemical vapor transport (CVT) method, was developed by Dr. Wenhao Liu, a postdoctoral research associate in the School of Natural Sciences and Mathematics. The paper is distributed in the journal ACS Nano.

“Although this material is not novel, our method for producing it differs from others. Our method is simpler, more direct, and yields much larger and higher-quality crystals than the conventional CVT method.”

Dr. Wenhao Liu, a postdoctoral research associate in the Department of Physics in the School of Natural Sciences and Mathematics,.

Liu, who works in the laboratory of Dr. Bing Lv, associate professor of physics and corresponding author of the report on this new technique, stated, “Although this material itself is not new, our method to create it stands out from other methods.” Our strategy is easier, more straightforward, and yields a lot more and better gems than the ordinary CVT technique.”

According to Lv (pronounced “love”), the synthesis method, which only requires the use of a box furnace, results in crystals that are one to two centimeters in size—ten times larger than those produced by other methods.

The research team was surprised by the exfoliated layers’ magnetic properties.

A chromium sulfide bromide crystal that was produced using a new method developed by Liu is examined by Dr. Wenhao Liu, a postdoctoral research associate, and Dr. Bing Lv, an associate professor of physics (left). The crystal’s magnetic properties may make the material easier to work with when making new devices. Credit: University of Texas at Dallas.

Each electron in a material possesses a property known as spin, which can be either up or down. The orientation of the spins is what determines the magnetic properties of the material. The material is ferromagnetic, for instance, when all of the spins are aligned in the same direction. On the other hand, the material is antiferromagnetic when the spins are aligned parallel but in opposite directions (antiparallel).

According to Lv, “typically, this magnetic ordering, or the alignment of spins, takes place immediately in a material.” Antiferromagnetic order increases and spreads throughout the crystal in three stages as the temperature is decreased, making our 2D material unique.

Attractive abnormalities — expansions in the greatness of ferromagnetic request — happen in the material at 185 kelvins (short 126.7 degrees Fahrenheit), 156 kelvins (less 178.9 degrees Fahrenheit), and 132 kelvins (less 222 degrees Fahrenheit).

“This is the first time that chromium sulfide bromide crystals have shown this phenomenon. Lv stated, “Because it goes against our intuitive thinking, I didn’t believe it when we first saw this.” This is a fascinating observation because certain magnetic memory devices may benefit from this kind of “soft” magnetism.”

The gem is steady in the air, a helpful and fundamental property for future exploration and conceivable use in elite execution gadgets, Liu said.

“Run-of-the mill precious stones can respond to water or oxygen in the air, which changes the substance or design of the gem,” said Liu, who is a co-lead creator of the report. “Because of this, crystals must frequently be capped with an inert substance. Our gem eliminates that obstruction, which makes it simpler to work with for new gadget manufacture and advancement.”

More information: Wenhao Liu et al, A Three-Stage Magnetic Phase Transition Revealed in Ultrahigh-Quality van der Waals Bulk Magnet CrSBr, ACS Nano (2022). DOI: 10.1021/acsnano.2c02896

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