High-density NDRO magnetic-thin-film memory devices

High-density thin-magnetic-film memory devices using double-layer storage films with NDRO properties were designed and tested. Use of the two double-layer films-one on the bottom and the other on the top of the bit-sense line-produced a structure that allows flux closure in such a way as to make possible a high-density film array. The devices tested were experimental arrays with densities of 4400 bits per cm 2 . Test results agreed well with those predicted from the theoretical model. Static measurements, as well as dynamic worst-case pulse tests for films and storage cells, were conducted, and the resulting signals and operating currents were determined.