The present disclosure provides a high heat radiation composite material including a hybrid filler comprising expanded graphite filled with expandable polymeric beads, and a fabrication method thereof. During a typical cleaning operation pressurized cleaning solution is dispensed through a rotating nozzle assembly inside the vessel. The first pit string P1 and the second pit string P2 are adapted so that the gaps between pits constituting those strings in accordance with address information are equal to, or less than, the width of the pits measured in a radial direction of the disk.