Researchers at IMDEA Nanoscience and other Spanish centers have managed to encapsulate so-called “cross-rotating molecules” in carbon nanotubes. These molecules can change the spin by stimulation such as temperature, which is an important fact in the development of spintronic devices and nanoelectronics.
Electronic devices are getting smaller and smaller, and scientists continue to shrink the size of their components. The demand for fast and efficient processes to achieve this goal has not stopped growing, and a solution may emerge. SpintronicsAn emerging technology that uses electrons and their charges Spin (Intrinsic angular momentum of the particle).
In this case, researchers from the Madrid Institute of Nanoscience (IMDEA) and the University of Seville have just published a paper in the journal. Nature Communications This study shows for the first time the conductivity of a single carbon nanotube with cross-rotating molecules.
Generally, magnetic molecules can bring new changes to conventional electronic devices. Specifically, Cross-rotating molecules (Spin divider, Shanghai Cooperation Organization(English) is a series of zero-dimensional (0D) functional units. These units exhibit radical spin changes triggered by changes in electrical structure and are activated by External stimuli, such as light, pressure or temperature.
This kind of spin switch makes SCO molecules have excellent functions and functions, which can be used in nanoelectronics. However, their insulating properties prevent these molecules from being fully utilized. Some research groups have embedded SCO molecules in a matrix of conductive materials, but the results are not fully compatible with the requirements of nanodevices.
The ability to manipulate matter on the nanoscale
The innovative system to effectively incorporate SCO molecules into conductive materials is to introduce SCO molecules into carbon nanotubes. Carbon nanotubes are one-dimensional (1D) materials that are resistant and lightweight. Most importantly, they are fine wires with good electrical conductivity, with a diameter of 1-5 nanometers and a length of up to centimeters.
For the first time, researchers encapsulated SCO molecules based on the element iron (Fe) in carbon nanotubes (SWCNT). The nanotube acts as a conductive body, which can transmit, protect and detect the spin state of the SCO molecule, thereby overcoming its inherent insulating properties.
The author used dielectrophoresis to study the transport of electrons through a single carbon nanotube embedded in a small nanotransistor. Therefore, they found a change in the conductivity of the nanotube, which was changed by the spin state of the encapsulated SCO molecule. The transition between the two conduction states is caused by the thermal switch, which was originally asymmetric: temperature The falling point is different from the transition point of the rising thermometer.
This fact opens up a hysteresis phenomenon (a material’s tendency to maintain one of its characteristics without generating irritation), which does not appear in crystalline samples, therefore, the potential application of the system appears “These systems are like tiny components. Because nanotubes exhibit a hysteresis cycle with changes in temperature, they can be stored at the nanometer level. They can also be used as spin filters (required for spintronic devices) because The nanotube will “sense” whether the molecule is spinning or not. Note. Enrique Burzurí, One of the authors of IMDEA Nanoscience.
Theoretical calculation support experiment
Theoretical calculations performed by researchers at the University of Seville provided support for the experimental results. During the conversion process, the orbitals of SCO molecules change, and their hybridization with carbon nanotubes also changes, which in turn changes the conductivity of carbon nanotubes.
The interaction between SCO molecules in the low-spin state and nanotubes is stronger. They are more difficult to change their state, which translates into a “jump” in the conductivity of the nanotube at a certain temperature, which depends on the initial spin state.
According to the researchers, the first encapsulation of SCO molecules in carbon nanotubes is a result of basic research, which helps to understand the behavior of these molecules in a small space and provides a solid coating for their reading and positioning. Floor. Nano-deposits.
The author hopes that this multi-dimensional hybrid material (0D-1D) can take advantage of the best properties of its constituent materials and use the spin state as an additional degree of freedom. Such tiny cables and switches can be produced on a preparatory scale and can represent an important step in the development of nanomagnetic systems.
Julia Villalva, Aysegul Develioglu, Nicolas Montenegro-Pohlhammer, Rocío Sánchez-de-Armas, Arturo Gamonal, Eduardo Rial, Mar García-Hernández, Luisa Ruiz Gonzalé (Luisa Ruiz-Gonzalez), José Sánchez Costa (José Sánchez Costa), Carmen Calzado (Carmen J.. “Spin state-related conductivity in single-walled carbon nanotubes encapsulating spin cross molecules “. Nature Communications, 2021.