Invited Paper TF+MI-WeM1
Recent Advances and Challenges in Magnetic Recording Media

Wednesday, October 30, 2013, 8:00 am, Room 102 C

For perpendicular magnetic recording (PMR) beyond areal density of 700 Gb/in², signal to noise ratio (SNR) and write-ability improvements are becoming extremely challenging to realize. The present exchanged coupled composite (ECC) recording medium has become quite complex and consists of multiple magnetic layers. To enable 1Tb/in² areal density, it is required to (i) improve grain isolation for SNR (ii) increase magnetic anisotropy for thermal stability and (iii) reduce all the dimensions, such as thicknesses of the magnetic layers and media grain size. Improvement in grain isolation with maintaining magnetic anisotropy poses challenges on material selection and process optimization and higher anisotropy materials limits the write-ability of the media. It was estimated that the media grain size <8nm can achieve higher SNR due to reduced jitter and transition noise. However, for last several years, the media grain size has hardly changed in optimized PMR media. The increased inter-granular exchange coupling in small grain size media degrades recording media noise characteristics. Also, thermal stability is compromised on media with small grain size. Here, we discuss recent developments and efforts on perpendicular recording media with small grain size and will present our major findings in terms of SNR, write-ability and thermal stability characteristics. We will also discuss advanced ECC media structure with multiple exchange break layers that offers advantages towards enabling reduced grain size. We also describe advanced characterization methods to quantify the effect of inter granular interactions and their relation with materials and sputtering processes.