METHOD AND DEVICE FOR MEASURING THE PARAMETERS OF SUPERCONDUCTING LAYERS

The method and the device can be applied in kryoelectronics and instrumentation engineering. By them the samples are not destroyed, simultaneous and synchronous measurements of the relations of the specific resistance , the real x' and the imaginary x" parts of the magnetic susceptibility and the critical current density Jc of the temperature layer are ensured, and the relations of these parameters on each other are directly produced, productivity is increased due to the simultaneous measurement of four parameters and the accuracy and reliability is considerably improved due to the elimination of inavoidable errors of non-identical conditions (different position of contacts, ageing of specimens in thermocycling) in the event of subsequent (consecutive) measurement. By the method, in the layer under investigation, DC is simultaneously passed and alternating magnetic field is applied on it having alternating amplitude where simultaneously the relation of the drop of voltage on the specimen are produced, and of the passed magnetic field from the temperature and from the intensity of the applied alternating magnetic field h, from where are determined: the relation of the specific reistance , of the real and imaginary part of the magnetic susceptability x' and x" and the critical density of the current Jc of the temperature and the applied magnetic field and the relations of these parameters on each other. The device consists of a substrate holder (1) which is in thermal contact with a thermosensor (2) connected to the control and data collection unit (3). A substrate with the layer under measurement (4) is fitted on the substrate holder, to which two current springing contacts (5) are simultaneously in touch, connected to a DC source (6) which is coupled to the control and data collection unit (3) and two springing voltage contacts (7) connected to the control and data collection unit (3), and on both sides of the substrate with the layer (4) two flat coils are fitted: an excitation (8) connected to a low frequency generator (9) the control input of which is coupled to the control and data collection unit (3), and a receiving coil (10) connected to the inputs of two synchronous amplifiers (11 & 12), the outputs of which are connected to the control and data collection unit (3), and their synchronization inputs being coupled to the low frequency generator (9).