An exchange-coupling layer consisting of a Co-Cr ferromagnetic layer laminated with a thin Ru layer on both sides was employed as a layer separating the recording layers in longitudinal HDD media. The Co-Cr-Pt-B recording layers, which are divided into sections of equal thickness, are ferromagnetically coupled via the antiferromagnetically coupled Co-Cr layer by a function of the thin Ru layers. Because of the separation of the recording layers, a reduction of about 30% in media noise was observed at 400 kFCI, and the thermal stability was the same as or better than that of the conventional type of synthetic ferrimagnetic media (SFM).
We investigated a hybrid thin film microstrip line with a polyimide (1 μm)/CoZrNb (1 μm)/polyimide (1 μm) sandwich structure and a polyimide (3 μm) microstrip line on the basis of electromagnetic field analysis, and we evaluated their characteristics for the fabricated device. Results showed that the distributed inductance of the polyimide thin film microstrip line depends on the operating frequency, because of the frequency-dependent magnetic shielding of the bottom ground plane. In the case of a hybrid thin film microstrip line, the distributed inductance is nearly constant, hence the characteristic impedance also becomes constant in the wide-band frequency range.
This paper investigates a magnetic-feedback-type neural circuit based on a variable-synapse coupling device using an MI microsensor array. The proposed variable-synapse device is a magnetic coupling system for multiplication and accumulation. Analogue magnetic memory will be utilized to store the values of synapse couplings. The pulse modulation characteristics of the magnetic-feedback-type neural circuit are demonstrated. A pulse neural network system could be devised, using the magnetic synapse in combination with a pulse density modulation circuit.