Scanning probe microscopy has long been seen as a possible basis for high-density data storage device [l,2]. Numerous means have been demonstrated with both the scanning tunneling microscope (STM) and the atomic force microscope (AFM) to write and detect surface features on nanoscale level. This approach has certain obstacles to overcome in order to become practical, however. One of the key difficulties is the low data rates typically achieved with scanning probe techniques. We have recently developed a means for reading and writing using STM with diamond tip. As a tip we use metal-doped type IIb diamond single crystal synthesized by the temperature gradient method under high pressure—high temperature (HPHT) conditions. The peculiarity of the proposed method is the use of the STM probe as the magnetic recording head, which allows one to achieve data recording rates comparable to the contemporary methods like heat-assisted magnetic recording (HAMR). The principal idea of our method is the utilization of STM diamond probe for both heating and magnetization of the local fragment of the magnetic surface by applying pulsing tunneling current. Recording is performed in STM with the probe placed on the fixed height over the surface. Reading is executed using the same probe in the magnetic force measurement mode. Due to the presence of the magnetic inclusions diamond probe acts as a permanent magnet mounted on the flexible membrane capable to deform when subjected to the magnetic field coming from the substrate’s magnetic layer. Axial membrane’s displacement in the course of reading is in the range of about 2 to 5 Angstroms and is measured by a special tunneling probe purposely placed on the back side of the probe. Proposed approach has a number of advantages over HAMR method. Heating of the magnetic spot on the surface can be performed without laser’s employment thus making the entire device much simpler, cheaper, compact and lightweight.
[1]. C. F. Quate, U.S. Patent 4,575,822, (1986).
[2] Xinxin Li , Jianqiang Han, Haifei Bao, Zunxian Yang, Sensors and Actuators A 133, 383 (2007).
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