985,656. Semi-conductor devices. INTERNATIONAL BUSINESS MACHINES CORPORATION. Jan. 26, 1962 [Feb. 2, 1961], No. 3020/62. Heading H1K. A circuit component comprises a conductive member and a a ferromagnetic member spaced apart by an insulating layer or barrier which is sufficiently thin to permit electron tunneling. A typical element is made by vacuum depositing an aluminium layer on a glass substrate, oxidizing it to a thickness of 20-30 Š by exposure to air at room temperature, and finally vapour depositing nickel over the oxide. Fig. 4 shows the current voltage characteristic, which is essentially independent of temperature between room temperature and 4‹ K., with the aluminium biased positive (curve A) and negative (curve B). Fig. 7 illustrates the change in voltage across the element with magnetic field under constant current conditions at two different temperatures. The voltage decreases with increasing magnetic field until magnetic saturation occurs when the voltage increases. Above the magnetic saturation level the voltage is strongly temperature dependent.