Thick films of superconducting YBCO as magnetic sensors

Abstract

Superconducting thick films of YBCO have been prepared successfully on MgO single-crystal substrate by a screen-printing method. A prototype magnetic field sensor has been made from these thick films and characterized using x-ray diffraction, scanning electron microscopy, and a magnetoresistance method. The microstructure of the YBCO thick film sensor was prepared in such a way so as to retain a small resistance R(B = 0) at liquid nitrogen temperature and at zero magnetic field. The R–T curves of the sensor revealed that the value of the resistance R(T) is highly sensitive to the relatively high applied magnetic fields in the temperature range from 75 to 85 K. The R–B curves were plotted at liquid nitrogen temperature. At relatively low applied magnetic fields (up to 100 G), the value of the normalized resistance was well fitted to the relation R(B)/R(B = 0) = 1+αB2, where α is a constant. However, at higher values of the applied magnetic fields, the normalized resistance exhibited an almost linear dependence with the applied field. The characteristics of the sensors showed considerable hysteresis at high ranges of magnetic field (from 100 to 500 G) with no significant hysteresis at low magnetic field (less than 100 G). The I–V curves at liquid nitrogen temperature were also measured after several thermal cycles for various values of applied magnetic fields. It was demonstrated that the I–V curves were independent on the number of thermal cycles and exhibited no significant change at relatively low currents and magnetic fields. That is, the I–V curves are reproducible under the above conditions. This suggests that a better performance of the sensor in the presence of relatively weak magnetic field is needed to get the ultimate sensitivity.

Sensitivity of YBa2Cu3O7 thick films to gamma rays

“…Finally, the pellet was cooled down to room temperature. Thick films of YBCO superconductor were prepared using the screen printing technique [12]. Fine grained precursor powder of YBCO was thoroughly mixed with an organic binder "ethylene glycol (HOCH 2 CH 3 OH)" to form a paste of appropriate viscosity.…”

Properties and Types of Superconductors

“…Due to the high transition temperatures of 110 K for Bi-2223 phase, these are applicable in numerous fields because of mechanical characteristics, higher upper critical magnetic field Hc 2 and greater critical current Jc. The BSCCO structures are potential candidates for commercial cables [102], magnets [103], MRI [104], SFCL [105] and magnetic sensors [106]. The properties Bi-2223 mechanism of superconducting are strongly connected with its hole concentrations, pinning ability and phase microstructure [107,108].…”

Magnetotransport and structural properties of superconducting BPSCCO thick film on MgO substrate

“…The processing of high temperature superconductor materials (HTSCs) in the form of thick films has been a major research activity in various research laboratories since the discovery of high-T c superconductors [1][2][3][4][5][6][7][8][9][10]. This is due to the large number of possible applications.…”

“…Several magnetic sensors based on various principles have been developed, with the specific requirements of each sensor being particular to its application. Each of these sensors has its own obstacles to be overcome for full integration into new field sensing technologies [1][2][3][4][5][6].…”

“…The resistivity versus magnetic field at various transport current densities for a broad temperature range has been studied and it was found that HTSC doped composites have much higher sensitivity to weak magnetic fields at liquid nitrogen temperature compared to pure HTSC ceramics and these composite materials can be used as active elements in magnetic field sensor devices [6][7][8]. Another magnetic field sensor made of YBa 2 Cu 3 O 7-δ (YBCO) thick films has been fabricated on MgO substrates using a screen-printing method [6]. The magnetic sensitivity of this film exhibited a strong response to applied fields up to 100 G. The normalized resistance was well fitted to a simple relation.…”