Barium Ferrite: Overview

Barium Ferrite (BaFe) is a new type of magnetic particle which can be greatly reduced in size to improve recording density without magnetic signal loss:

  • Fujifilm’s LTO 7 and future generations of LTO will use BaFe particles with NANOCUBIC technology for a thin and uniformly coated magnetic layer.
  • BaFe is already used and proven in enterprise products such as Oracle’s T10000 and IBM’s 3592 tape cartridges.
  • Fujifilm patented technology.

NANOCUBIC technology is composed of the following three categories: NANO Particle, NANO Dispersion and NANO Coating.

  • Each technology undergoes continuous improvement and refinements
  • BaFe is the latest technology in NANO Particle

Size

Current LTO 5 metal particles (MP (G5)) are approximately 40nm in size whereas BaFe particles are approximately 20nm. The smaller size enables much higher recording density resulting in super high capacity data cartridges.

In addition, Fujifilm succeeded in developing even smaller BaFe particles and demonstrated 123 billion bits per square inch recording density with IBM in 2015. The demonstration points to the possibility of developing a single tape cartridge capable of holding 220 terabytes of uncompressed data. These much smaller BaFe particles will be applied for future BaFe products.

Metal vs. Barium Ferrite

Metal particles require a protective passivation coating to prevent oxidation. The passivation layer also limits the reduction in particle size that can be achieved. BaFe particles are oxides so a passivation layer isn’t needed. Smaller particles with higher stability can be achieved with BaFe.

MP (G5) particles have an acicular shape. BaFe particles are hexagonal disc-shaped. The hexagonal shape allows much better orientation control and lower flux density resulting in higher signal to noise ratio.

Magnetization Axis with Passivation Layer

MP Acicular ShapeMagnetization no Passivation Layer

BaFe Hexagonal Disc Shape

 

Metal Particle

Metal Particle
(FeCo alloy) LTO 5

Barium Ferrite Current

Barium Ferrite
(BaO(Fe2O3)6 Oxide) Current

Barium Ferrite Future

Barium Ferrite
(BaO(Fe2O3)6 Oxide) Future

Scanning Electron Microscope image of the tape surface: MP and BaFe particles appearance as coated onto the tape support. Note the relative size and shape differences.

MP Coating

MP (G5)

BaFe Coating

BaFe

BaFe particle characteristics allow for better orientation control and therefore higher Signal to Noise Ratio (SNR). Perpendicular orientation will be applied to future BaFe particles.

BaFe PArticle Orientation

BaFe Recording Characteristics

Output SNR of BaFe particle tape is far better than that of MP (G5) tape enabling higher linear density and recording capacity.

BaFe Particle Comparison Chart

Barium Ferrite has better frequency characteristics compared to metal particles resulting in a significantly increased margin of recording capability. Therefore, it is expected that Fujifilm LTO 6 can be written to and read even when the ability of the drive’s recording head has diminished after repeated use.

Data Storage Frequency based on BaFe

Oxidation is one of the causes of magnetic particle deterioration with possible data loss. However, Barium Ferrite is already oxidized and therefore has a much longer life compared to metal particles.

  • In Fujifilm’s experiments, BaFe withstands realistic storage environment simulations and proves its reliability over more than a 30 year time period.
  • MP shows slight degradation in magnetic signal over 30 years, although not detrimental to read/write performance.BaFe Degradation Chart