Analysis of Magnetization State of Recording Head Tip with Narrow Track

• Published in: Japanese Journal of Applied Physics Vol. 39; no. 7R; p. 3957
• Main Authors: Shimizu, Yusuke, Shiiki, Kazuo
• Format: Journal Article
• Language: English
• Published: 01.07.2000
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.39.3957

Three-dimensional micromagnetic simulation coupled with electromagnetic calculation of continuous medium was carried out to investigate the magnetization state of the narrow track recording head tip. The entire recording head is treated as a macroscopic magnetic material. The effect induced by the recording current is incorporated into the micromagnetic simulation of the head tip as the boundary condition. First, the magnetic flux density in the entire head and the external magnetic field are calculated by the magnetic moment method. Then the micro-magnetization states of the head tip are solved using the Landau-Lifsitz-Gilbert equation under the boundary condition of the magnetization in external magnetic fields. Closure domains of which the magnetization direction of the main domains is the bit direction, are formed in the head tip in the case of track direction easy axis. As the recording current increases, the induced magnetic field parallel to the bit direction moves the 180° domain wall in the tip. This problem cannot be overcome either by changing the easy axis or by increasing the anisotropy strength. The laminated magnetic film tip with nonmagnetic spacers is able to suppress the domain wall motion.