Mozaic Technology Innovation

Superlattice Platinum-Alloy Media

Combating Magnetic Instability at the Nanoscale

To develop a storage layer that offers higher magnetic coercivity, we crafted a superlattice structure where the precise arrangement of each atom plays a critical role.


A significant advancement in magnetic storage media.

For HAMR technology, where data must be stored in the form of magnetic bits that are closer together than is possible with conventional PMR hard drives, the recording media had to be rethought from the ground up.

The advanced materials and structures used in Seagate’s Mozaic 3+TM platform support data writing that’s far more precise than any previous hard drive technology.


Its essence lies in the use of platinum (Pt) and iron (Fe) particles.

Within the superlattice platinum-alloy media, each nanoparticle, only a few nanometers in size, acts as an individual bit of data.

This fine granularity is made possible by the media’s high magnetic anisotropy—which means that the magnetic orientation of the material remains steady over time, ensuring that each bit is stable and unaltered by the writing of adjacent data.


The media’s unique magnetic alloys favor a predetermined magnetic orientation.

This is key to stabilizing the magnetic state of individual bits, thereby reducing their susceptibility to thermal fluctuations.

Its high magnetic anisotropy provides the stability needed for recorded bits achieving record areal densities—bits that are placed together more densely than in any other hard drives in history.


Achieving order within the media involves sophisticated manufacturing.

Epitaxial growth is used to deposit FePt thin films on crystalline underlayers on a special glass substrate. These underlayers serve as a template, dictating the orientation and ordering of the FePt grains during the deposition process.

Subsequent annealing at high temperatures further promotes ordering in the FePt grains, leading to a phase transformation that enhances the media's magnetic properties and grain alignment.

This intricate and carefully controlled process provides a robust, stable platform for high-density data storage.