Quasistatic Bubble Propagation in 1.5 μm Period Ion-Implanted Tracks for 64 Mbit Magnetic Bubble Memory Devices
Ion-implanted tracks with a 1.5 μm period for use in 64 Mbit magnetic bubble memory devices have been fabricated and operated. The bubble material used was (BiSmLu)3 (FeAl)5O12 garnet film, supporting 0.45 μm bubbles. The resist mask patterns for implantation were formed using a 1/10 reduction projection aligner, using rectangular patterns on a reticle. The bubble propagation tracks were fabricated by double deuterium implantation and annealed at 400°C for 30 minutes, with an SiO2 layer deposited on the garnet surface to stabilize the implanted layer. An operating bias field margin in excess of 7% was stably obtained in quasistatic bubble propagation. This shows that the ion-implanted devices have great potential for use in 64 Mbit magnetic bubble memory devices.
Design and characterization of ion-implanted tracks for 16 Mbit/cm 2 storage density bubble memory devices
The ion-implanted propagation tracks with contiguous disk patterns (CD tracks) have been confirmed to be better for high density propagation tracks (≥ 16 Mbit/cm2) than those with snake patterns (snake tracks), because of less interactions between bubbles on the other side in the same track. The CD tracks with 1.8 µm × 2.0 µm cell size for 0.5 µm bubbles have been evaluated. The large operating bias field margin of 12.4 percent is obtained at the quasi-static operation with rotating field H R of 60 Oe. The minimum rotating field is 40 Oe. Interdigital folded minor loops are proposed and operated. The proposed minor loops are composed of straight propagation tracks connected alternately to relax the in-side turns. The overall operating margin of 8.4 percent (46 Oe) is obtained at H R = 60 Oe. The feasibility of 16 Mbit/cm2storage density bubble memory devices is confirmed.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.