Showing papers by "Harald Schmidt published in 1989"
TL;DR: In this paper, superconducting YBa 2 Cu 3 O x thin films were prepared by magnetron sputtering using YBa 1.5 O x and YBa 4 O x targets, and the microstructure of the films was analyzed by transmission electron microscopy.
Abstract: Superconducting YBa 2 Cu 3 O x thin films were prepared by magnetron sputtering using YBa 2 Cu 3 O x and YBa 2 Cu 4.5 O x ceramic targets. Thin films deposited on SrTiO 3 substrates had superconducting transition temperatures between 60 and 78 K. The substrate temperatures during deposition ranged from 520 to 725°C. The microstructure of the films was analysed by transmission electron microscopy. Extended defects due to the deviation from YBa 2 Cu 3 O x stoichiometry were identified. Thin films deposited on LiNbO 3 and SiSi 3 N 4 were c oriented and had superconducting transitions at T c of 67 K and 46 K respectively.
3 citations
Patent•
16 May 1989TL;DR: In this paper, the contactless proximity switch is used as wheel sensor in railway signal systems in which high travelling speeds must be expected, and the sensor voltage can be changed when influenced by metal parts.
Abstract: A contactless proximity switch remotely fed via a two-wire line should also properly signal inferences of very short duration by means of current pulses of a predetermined minimum duration with little current consumption. The contactless proximity switch consists of a sensor (SR), the electrical behaviour of which can be influenced by metal parts and the sensor voltage (US) of which, which can be changed when influenced, controls an electronic threshold switch (OP) which also emits pulses of a predetermined minimum length (t2/t4) with influences of only very short duration due to a special external circuit (C1, R4, D2). The contactless proximity switch is advantageously used as wheel sensor in railway signal systems in which high travelling speeds must be expected.