An apparatus and method is disclosed for orienting the magnetic anisotropy of longitudinal patterned magnetic recording media. A disk-shaped longitudinal granular magnetic recording medium is provided having a high orientation ratio in the circumferential direction. The medium is then patterned to form a uniform array of magnetic islands. The magnetic islands are then irradiated with ions to increase the magnetic exchange coupling between the grains of each island. This aligns the axes of magnetic anisotropy of the individual grains with the average axis of magnetic anisotropy of the grains, thereby aligning the magnetic anisotropy of each island along the circumferential direction.