Effect of Anodized Aluminum Oxide Underlayer on the Magnetic Properties and Structure of Smtbco Magnetic Films

A self-ordered hexagonal array of nanopore was fabricated by anodizing a thin film of Al on glass and subsequently SmTbCo perpendicular thin film was prepared on the AAO underlayer by magnetron sputtering. The vibrating sample magnetometer (VSM) measurement reveals that introducing anodized aluminum oxide (AAO) underlayer can increase the coercivity of SmTbCo thin film from 370kA/m to 530kA/m. With the decrease of hole diameter of AAO underlayer, the coercivity and remanence squareness ratio of SmTbCo magnetic thin film are increased. SEM observations indicate that the SmTbCo thin film deposited on the AAO underlayer consists of a column structure which is attributed to the AAO underlayer selfa2ordered hexagonal array of nanopore structure, The enhancement of coercivity caused by heterogeneous structure extends SmTbCo thin film ˉs application in super high density perpendicular magnetic recording.