US 9928864

US Patent 9928864, titled "Multilayer exchange spring recording media," was issued on March 27, 2018. The application, filed on November 17, 2009, lists Dieter Suess as the inventor. The current assignee is Mr Technologies GmbH, while the original assignee was an Individual.

The abstract describes a magnetic recording medium featuring a multilayer exchange spring design. It comprises a magnetically hard magnetic storage layer strongly exchange-coupled to a softer nucleation host. The exchange coupling can be direct or via a thin coupling layer. The hard magnetic storage layer possesses strong perpendicular anisotropy. The nucleation host consists of one or more ferromagnetic coupled layers, where the anisotropy increases from layer to layer. The anisotropy in the softest layer of the nucleation host can be up to two times smaller than that of the hard magnetic storage layer. The lateral exchange between grains is minimal. This design significantly reduces the coercive field of each grain while maintaining the thermal energy barrier of the hard layer. The coercive field of the total structure is inversely related to the number of layers in the nucleation host, addressing the writeability problem in perpendicular recording media.

Independent Claim Overview (Claim 1):

Claim 1 describes a magnetic recording medium structured to enhance data storage capabilities. It consists of:

• An essentially non-magnetic substrate serving as the base.
• An underlayer formed directly on this non-magnetic substrate.
• An exchange-coupled magnetic multilayer structure built on the underlayer. This multilayer structure itself includes two key components:
  • A hard magnetic storage layer, which has a first coercive field (H_s) greater than 0.5 Tesla. This layer is situated between the underlayer and the next component.
  • A nucleation host layer, which, if considered independently (without the hard magnetic storage layer), would have a second coercive field (H_n) lower than that of the hard magnetic storage layer (H_n < H_s).
  • The nucleation host is positioned on top of the hard magnetic storage layer and is exchange-coupled to it.
  • A critical feature of this nucleation host is that it is composed of multiple ferromagnetic layers, and the anisotropy constant (K) progressively increases from one layer to the next within the nucleation host.

Uncertainty Regarding CAFC 2026 Dockets:

Based on the provided patent text and additional searches, there is no authoritative information explicitly indicating that US patent 9928864 is currently involved in litigation within the CAFC 2026 dockets. The patent text does mention a "PTAB case IPR2026-00014 filed (Not Instituted - Procedural)" which is a Patent Trial and Appeal Board (PTAB) proceeding, not a case before the Court of Appeals for the Federal Circuit (CAFC). The searches conducted did not return any specific CAFC cases for patent 9928864 for the year 2026.