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In this paper, we demonstrate high-performance giant magnetoresistive spin transistor (GMRST) and magnetotunneling resistive spin transistor (MTRST) which could be used as magnetic pickup head and magnetoresistive random access memory (MRAM). This kind of spin device is based on the technologies of giant magnetoresistance (GMR) and tunneling magnetoresistance (TMR) effects together with a p-n junction. The junction is used as a potential barrier to select spin electrons. In case of GMRST the collector current, Ic, varies from 464 pA at magnetically parallel state to 309 pA at magnetically antiparallel state and gives a percentage change of about 50% at room temperature. As for the MTRST, the change of Ic is about 45% at room temperature with current varying from 2.9 to 4.2 μA. Memory effect, which is the intrinsic behavior of magnetic materials, is also demonstrated. [ABSTRACT FROM AUTHOR]

Presents information on a study which investigated the cogging torque and dynamic performance of a designed single phase brushless direct current spindle motor for use in hard disk drives and digital-video disk drives. Experimental details; Results and discussion; Conclusions.

Investigates the torque of magnetic coupling with different magnetic poles by theoretical computation with two dimensional modeling processes of finite element analysis. Experiment and computation of magnetic coupling device with different magnetic poles; Results and discussion of the computation and experiment of magnetic coupling between two magnets; Conclusions.

A spin tunneling transistor (STT) was designed by growing a magnetic tunneling junction (MTJ) on a p-n junction. The magnetocurrent (MC) ratio of the collector can be stabilized roughly above 40% at VE = 1.25 ± 0.25 V with the transfer ratio (Ic/IE) of 2.88%, while the transistor is operated in the common collector circuitry with an emitter bias and a base resistor at room temperature. The output current can be more than 4 μA when the magnetic moment of the base layer is oriented parallel to that of the emitter layer. The high performance is achieved mainly due to the base resistor, which can push our STT to the right working region and enlarge the MC ratio of the collector. [ABSTRACT FROM AUTHOR]

Investigates the torque of a magnetic gear system with different magnetic poles by computer-aided simulation with two dimensional modeling processes of finite element analysis. Computing consideration; Results and discussion.

Presents a study of the reduction of cogging torque in permanent magnet motors. Information on cogging torque; Computational considerations.