While the amount of data in the world is expected to increase in the future, in order to further increase the capacity of the HDD and improve the data transfer speed, it is a rational design after accurately grasping the operation of the HDD write head. Must be.However, since the write head has a fine structure of 100 nanometers or less and performs high-speed magnetization reversal within 1 nanosecond, it has been difficult to actually observe its operation.

　Therefore, Toshiba Co., Ltd., High Brightness Photon Science Research Center (JASRI), and Tohoku University have jointly developed a new analysis technology for HDD write heads using synchrotron radiation from the large synchrotron radiation facility SPring-8.With this technology, we succeeded for the first time in the world in imaging the magnetization behavior of the write head with an accuracy of 100/1 billion second. Time-resolved measurement is realized by timing control that synchronizes with the X-ray pulse periodically generated from SPring-8 and reverses the magnetization of the write head in a cycle of 10/1 of that.With this method, it is said that there is a potential to achieve even higher resolution if the elements used for condensing X-rays are improved in the future.

　With this technology, we captured how the magnetization reversal of the write head is completed within 1 nanosecond, and the spatial pattern of magnetization that occurs in the shield part due to the magnetization reversal.This is the first study to capture the magnetization behavior of the write head during operation with such high spatiotemporal resolution.

　By using this method, it becomes possible to analyze the operation of the write head with high accuracy, and it is expected that the development of the next-generation write head that enables further improvement of HDD performance will gain momentum.

Paper information:[Journal of Applied Physics] Time-resolved imaging of an operating hard-disk-drive write head using nano-beam xray magnetic circular dichroism