Benefits of Prussian Blue in storing information at the atomic level

In the Prussian blue family, there is a compound capable of acting as a switch: initially it has no magnetism, but it can become magnetic thanks to the action of light and return to its original state. thanks to the heating.

Scientists at the Institute of Molecular Chemistry and Orsay Material and the Laboratory of Inorganic Chemistry and Molecular Materials have demonstrated that this property change is due to the variation of all positions of the integers. death, caused by light. Such compounds have the ability to remember binary information like that, which can be used as storage bits in future computers.

A substance that converts flexibly (Photo: nature.com)

In the field of computers, the need of society needs to increase the amount of information storage is increasing and has led to the birth and development of nanotechnology: Store a huge amount of information is extremely large The smaller the disc the better and the faster the better. The first hard disk, RAMAC, created by IBM in 1954, weighs 1 ton and stores 5 magabytes.

In laptops and MP3 players today, hard disks store several gigabytes and weigh only a few hundred or even a few dozen grams. To further reduce these devices and give users more choices, many scientists are making new materials that can be flexibly transformed, such as those that can be transferred from one state (OFF = 0) to another state (ON = 1) thanks to the impact of external impulses (changes in temperature, pressure, light, electrical impulses or magnetism. In this way , chemists from the two research groups hope to succeed in storing information at the atomic level.

They are studying Prussian blue. By replacing some of these atoms or iron with cobalt, they convert this ancient time-changing dye into a compound that can act as a switch: when illuminated with red light in heat low (-150 ° C), this compound changes from non-magnetic (OFF) to magnetic (ON) state in a stable way over time. If it is heated, it will return to the off state. This state change is due to the conversion of an electron from cobalt to iron (and vice versa) by absorbing light or thermal energy.

Today, by using synchrotron radiation, chemists have observed the transformation of all the positions of atoms in space, created by the conversion of electrons from one atom to another . When electrons move from the iron atom (OFF state) to the cobalt atom (ON state) thanks to red light, three-dimensional bonds between cobalt, nitrogen, carbon and iron atoms are initially bent. should be straight. This structural change is responsible for the existence of its magnetic state and stability over time.

Atomic-level understanding of mechanisms related to ON / OFF switching is an essential first step in envisioning the substances that can be used in industry to store information in billions. Atomic ratio.

These new compounds are capable of perfectly reproducing the storage function of traditional ingredients. Because soon, it will be impossible to reduce the size of traditional components without losing their memory function, scientists are imagining the materials that can take on and meet the needs. of society about the storage of miniature information.

Thanh Van