NVRAM, Non Volatile Random Access Memory

2023: Promising Magnetic Material Found for Ultra High Density Non-Volatile Memory

Scientists from MIPT together the French with colleagues found a material whose magnetization can be reliably fixed at several intermediate values. This paves the way for the creation of non-volatile memory for hard drives ultra-high density. storages information The study is published in the journal Small Methods. This was announced on November 22, 2023 by representatives of the Moscow Institute of Physics and Technology.

As reported, despite the active use of solid state drives as memory for computers, magnetic memory-based hard drives are still quite common due to their cheapness and reliability. They are based on encoding bits (zeros or ones) using the correct magnetization of domains - small areas on the working surface of the hard disk.

Magnetization itself is the product of the orientation of a huge number of atomic spins. Zero and one in the domain are achieved when all spins are oriented either up or down. At the same time, intermediate options are also permissible, when only a part of the spins "looks" in the right direction. Such an approach would allow more than one bit to be encoded in one domain, which would optimize the information capacity of hard disks.

In order to put this idea into practice, materials are required in which the intermediate magnetization states are stable, otherwise the memory will lose reliability. Scientists from the Center for Advanced Methods of Mesophysics and Nanotechnology MIPT and their colleagues from several French institutes in their search drew attention to the compound BaFe2 (PO4) 2, which they simply called BFPO. This material demonstrates the stability of blast furnace walls after freezing below 15 kelvins. At this temperature, there is a phase transition from a soft magnet to a super solid. In the latter case, domains stabilize so strongly that a magnetic field of more than 14 tesla is required to re-magnetize them.

This is due to the fact that BFPO is a quasi-two-dimensional ising ferromagnet. The material can be represented as layers within which the spins of atoms exhibit collective ordering. Such a structure gives the material a strong magnetic anisotropy, that is, a different response depending on the direction of the applied magnetic field. A distinctive feature of BFPO is the very narrow domain walls. To make sure, physicists examined the samples using magnetic force microscopy at various temperatures and magnetic fields. As the calculations predicted, the domain structure is a collection of bands that form a bizarre labyrinth.

Small Methods

We at our center have a number of techniques, one of which is cryogenic magnetic force microscopy. This technique made it possible to unambiguously characterize this material. For the first time, we demonstrated its domain structure and its dynamics when exposed to an external magnetic field and temperature. It should be noted that in France such a study could not be carried out. But we also had to work hard: the studied crystals have microscopic dimensions, and for study we had to place them on a specially prepared substrate with a micromanipulator. They are also insulators, which leads to the accumulation of electric charge on their surface and additional, harmful for us, interaction with the cantilever. The material has various physical properties. It is necessary to think about a possible application in microelectronics. told Vasily Stolyarov, Director of the Center for Advanced Methods of Mesophysics and Nanotechnology of MIPT

Vasily Stolyarov, Director of the Center for Advanced Methods of Mesophysics and Nanotechnology of MIPT

The temperature at which it was possible to achieve the manifestation of some properties of the material is uncomfortable for its wide use, but it is worth noting the possible use of it in superconducting digital and quantum electronics, where in November 2023 there is an acute problem of cryogenic non-volatile memory.

2019: MIPT scientists' breakthrough in creating non-volatile memory cells

On November 27, 2019, the Moscow Institute of Physics and Technology (MIPT) informed TAdviser that a group of researchers from the MIPT laboratory of functional materials and devices for nanoelectronics and colleagues working in Germany and the United States made a breakthrough towards the creation of unknown types of non-volatile memory cells. Scientists managed to create a technique for measuring the distribution of electrical potential inside the so-called ferroelectric capacitor - the basis of the memory elements of the future, which will work an order of magnitude faster than flash drives or solid-state drives existing in November 2019 and withstand a million times more rewriting cycles. Read more here.

See also

• DRAM Memory (Global Market)
• 3D NAND Flash Memory
• Ferroelectric RAM, FeRAM, FRAM
• ReRAM - Resistive Random Access Memory
• MRAM (magnetoresistive random access memory)