Whether it's a smart phone with you or a supercomputer deployed in the computer room, having more storage space and capacity is their common technology 'dream'. With the deepening of materials research, single-molecule magnets have also emerged. The use of single-molecule magnets as information storage units to achieve ultra-high-density information storage has also become a goal that scientists are striving for.
Since the first single-molecule magnet Mn12 was first discovered in 1993, the research on the magnetoelectric properties of single-molecule magnets has continued to deepen. Recently, researchers from the Institute of Physics of the Chinese Academy of Sciences and Nankai University have for the first time in a rare earth-containing cesium (Dy). In the single-molecule magnet, a significant magnetic-dielectric effect was observed. Recently, the reporter interviewed one of the testers, Dr. Wang Yuxia from the Department of Chemistry, Nankai University, and listened to her about how the electric field makes the single-molecule magnet 'obedient' and magnetically The wonderful process of regulation.
Big 'belt' - with more data storage capacity
A single-molecule magnet is a special type of magnet composed of discrete, non-magnetically interacting nano-sized molecular units. Each molecule is an independent magnetic functional unit that exhibits superparamagnetism at high temperatures and appears at low temperatures. Hysteresis and magnetization quantum tunneling behavior.
Wang Yuxia told the Science and Technology Daily that the magnetic properties of ordinary magnets are mainly derived from the magnetic interaction between adjacent paramagnetic centers. Due to the size of the nano-magnetic particles, some special quantum behaviors are generated. Single-molecule magnets can be like tiny magnets. Convert between two states of '0' (molecular orientation in the direction of the magnetic field) and '1' (the direction of the molecular orientation in the reverse magnetic field). 'It is this characteristic that gives the single-molecule magnet a large 'weight', Significantly increasing the density of information storage means that storage devices made from such magnets have greater data storage capabilities. 'Wang Yuxia said, 'Single-molecule magnet technology can store more than 200 megabits per square inch (6.45 cm2)). Data, if applied to quantum computers in the future, is expected to achieve ultra-high-density information storage.'
Have 'personality' - maybe 'lazy to steal the road'
Magnetism and electricity are two basic properties of matter. As early as more than 100 years ago, scientists such as Maxwell unified magnetism and electricity in the framework of electrodynamics. Scientists have been trying to explore the coupling of magnetic and electrical properties in solids. Regulation.
"The Book of Songs" has a cloud of 'pitch me papaya, and reported it to Qiong'. Scientists have been hoping to see this 'harmonious' electromagnetic coupling scene on single-molecule magnets. Wang Yuxia told reporters that the magnetic behavior of single-molecule magnets They are all manifested by the slow magnetic relaxation of a single molecule. 'The so-called relaxation, in layman's terms, is time.' Seeing the reporter's face ignorant, Wang Yuxia explained, "It's like a man going over the mountains, single-molecule magnet performance." Magnetic behavior, its electrons also need to climb from one side to the other side through a high slope. Usually this will take some time. This time is relaxation. ' Interview reporter learned that due to the energy level of rare earth elements More, the electrons of a single-molecule magnet may be 'sneaked in the near-track', and the energy consumption from the side to the other side is less, and the relaxation time is shorter. 'These are not conducive to single-molecule magnets. The expression of magnetic properties. 'Wang Yuxia said, 'Our research hopes to better balance the 'personality' of single-molecule magnets, and achieve effective and reversible regulation of magnetic properties through electric fields.
This orderly controllable magnetoelectricity means high conversion efficiency, which also means considerable application prospects. 'For example, in magnetic storage, magnetic recording has a fast reading speed and slow writing, and ferroelectric recording is complicated to read. Faster, if you use multi-ferromagnetic materials, you can achieve ultra-high-speed reading and writing process at the same time. 'Wang Yuxia said.
Broad prospects - storage density is hundreds of times higher than current technology
With the rapid development of wireless communication technology, information storage technology, electromagnetic interference technology, etc., people have put forward higher requirements for material selection and device miniaturization and integration design. The magnetoelectric heterostructure of single-molecule magnet has Energy has many advantages such as free conversion between magnetic field and electric field and large magnetoelectric conversion coefficient. Therefore, it has broad application prospects in sensors, multi-state memories and RF microwave devices. In the interview, Wang Yuxia also revealed that they prefer to synthesize through chemical synthesis. The method attempts to introduce ferroelectric polarization by breaking the spatial inversion symmetry, enhance the magnetoelectric coupling effect, realize the electric field's regulation of the magnetic or magnetic field, and obtain a novel magnetoelectric material with both single-molecule magnet and ferroelectric behavior.
'Single-molecule magnets show magnetic memory effects as a necessary factor for all stored data. Theoretically, using a single molecule for data storage can provide a hundred times higher data density than current technology.' Wang Yuxia said, this also means that single-molecule magnets have Broad application prospects.
At present, the magnetic structure of single-molecule magnets has been relatively clear. Wang Yuxia told reporters that the properties of single-molecule magnets can be predicted based on the configuration of the molecule. If the molecule belongs to a symmetrical configuration with large magnetic anisotropy, it is more likely to become Single-molecule magnet. The reporter learned that in this experiment, Wang Yuxia and his research partners used a slow evaporation method to synthesize a single crystal sample of this rare earth lanthanum monomolecular magnet, which is up to the order of millimeters. The spin-orbit-coupled erbium ions are in a slightly distorted octahedral coordination field and have uniaxial anisotropy, which is beneficial to the formation of single-molecule magnets. The measurement of AC magnetic susceptibility and DC magnetization determines the single-molecule magnet. Low temperature magnetic relaxation behavior and magnetic anisotropy. This study also laid a solid foundation for subsequent electrical continuous measurement observation.
