Magnetism on the Rise: MRAM, Graphene, and Solar

magnetic-spin-memory With the recent influx of graphene research breakthroughs in attaching magnetic effects to graphene sheets, and MRAM associated material science advances showing more promise for nvram type magnetic and spin based memory, companies in the MRAM space like:

  • Everspin Technologies (a spinoff from Freescale in 2008, pushing ST-MRAM and who hit 16mb stacks last year [link, profile]);
  • Micromem Technologies Inc. [MMTIF],
  • Spin Transfer Technologies LLC [link] (out of NYU tech, and weighted towards “orthogonal spin transfer magnetoresistive random access memory”, OST-MRAM), and
  • Honeywell Microelectronics (who last year promised an MRAM module that “will have radiation assurance of greater than 1 megarad total dose, and capable of maintaining data for greater than 15 years without refresh…” article, parent profile, which may also benefit future non-aerospace applications such as remote radiation sensing, ala the Fukushima Daiichi nuclear power disaster…)

… will hopefully see a boost in external investor qualifying and internal contractual interest for further research, development and fabrication of magnetic spin based memory technology. Even though there has been a lot of money invested over many years in the area, MRAM has had a kind of consumer-backburner presence, partly because the (extreme!) costs of MRAM fab plants have been biased towards squeezing out the easily available cost points of flash and EEPROM.

But with recent advances in:

  • Attaching magnetic effects to graphene [Nature], showing promise for years now [PhysOrg];
  • Possible (read: half impossible?) Photovoltaic applications derived from the Magnetic Fields surrounding Light [UOM, from the his months Journal of Applied Physics, (paper), on “Optically-induced charge separation and terahertz emission in unbiased dielectrics, by W. M. Fisher and S. C. Rand”];
  • An increased interest in medical [lab-on-a-chip], radiation (rad-hard), automotive, low power and temp hardened tech

…all look like they may allow MRAM to expand out of its primary role as embedded, small, highly tolerant and hardened,flight and endurance qualifying memory. However, it wont be alone. There are a host of other non-volatile memory (nvram) technologies competing for scale, low-power, switching speed, durability and longevity, and above all price point that make the non-volatile memory field one of the most volatile areas of research on the verge of production.

MRAM itself has a host of competing focii: STT-RAM (SPRAM), aka Spin Momentum Transfer, Spin Transfer, Spin Injection, Spin Transfer Switching, or Spin Torque Transfer MRAMs rely on changing the electron spin with direct electrical current, instead of induced magnetic fields. TAS-MRAM, or Thermal Assisted Switching memory, shares some properties with Phase Change memories (aka PCME, C-RAM, PRAM, PCRAM, Ovonic Unified Memory, or Chalcogenide RAM) in that it relies on short heating of magnetic tunnel junctions during a write process, and keeps the tunnel junctions stable at cooler temperatures; and Vertical Transport MRAM, (VMRAM), which benefits from high-densities, but uses perpendicular currents to the plane, in order to switch spintronic memory element states.

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