{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-8529989","patent":{"patent_number":"US-8529989","title":"Method for manufacturing magnetic recording layer having two or more layers","assignee":null,"inventors":[],"filing_date":"2008-10-02T00:00:00.000Z","publication_date":"2013-09-10T00:00:00.000Z","cpc_codes":["G11B","G11B"],"num_claims":7,"abstract":"The present invention relates to a method for manufacturing a perpendicular magnetic recording medium including a nonmagnetic substrate, and at least a soft magnetic under layer, an orientation control layer, a magnetic recording layer constituted of two or more layers and a protective layer formed on the nonmagnetic substrate, the method including a step of forming a first magnetic recording layer having a granular structure constituted of ferromagnetic crystal grains and crystal grain boundaries made of a nonmagnetic oxide or nitride on the nonmagnetic substrate side, a step of forming a second magnetic recording layer constituted only of ferromagnetic crystal grains, a step of forming a surface unevenness control layer for decreasing surface unevenness of the first magnetic recording layer located between the first magnetic recording layer and the second magnetic recording layer, and a step of heating the nonmagnetic substrate so as to decrease a surface roughness Ra of the second magnetic recording layer to less than 2 nm. The present invention also relates to a magnetic recording and reproducing apparatus using the magnetic recording medium."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Method for manufacturing magnetic recording layer having two or more layers","description":"The present invention relates to a method for manufacturing a perpendicular magnetic recording medium including a nonmagnetic substrate, and at least a soft magnetic under layer, an orientation contro","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-8529989","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-8529989","citation_suggestion":"Patentable. \"Method for manufacturing magnetic recording layer having two or more layers\" (US-8529989). https://patentable.app/patents/US-8529989","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-8529989","json":"https://patentable.app/api/llm-context/US-8529989","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-05-30T19:46:37.588Z"}