8. INTERNATIONAL SCIENTIFIC RESEARCH AND INNOVATION CONGRESS, Baku, Azerbaijan, 22 - 23 June 2024, pp.140-141
Co/Cu superlattices were potentiostatically electrodeposited on a glass substrate coated ultrathin Ni layer. For the superlattices, the Co and Cu layer thicknesses and the total thickness were changed. The crystal structure was determined by X-ray diffraction technique and found that the superlattices have a cubic structure. The morphological properties were studied by scanning electron microscopy. The magnetic properties were investigated by vibrating sample magnetometry. The magnetoresistance measurements were performed by linear prob. At the end of these measurements and investigations, it was decided that a sample of Glass/Ni(30nm)/70[Co(3nm)/Cu(0.6nm)] is convenient for sensor development.
For sensor design, an ESP32 integrated circuit with an internal current source up to 30 mA and controlled by a computer, and an ADC 1220 analog-digital converter working compatible with this circuit were used. They were chosen by considering the factors of common usage, cheapness, easiness and coordination with the superlattices used as sensor. The printed circuit board (PCB) cart, on which the integrated circuit, converter and sensor were mounted, was designed as a 4-layer board. It was obeyed basic EMC rules to prevent signal distortion. The sensor circuit was designed as a Wheatstone bridge, and as to allow applying current when needed. The measurements were performed by a fabricated prototype in the magnetic field of ± 2 T. As a result, the detection of the variation in the magnetic field was obtained by the superlattices used as a sensor. It was concluded that superlattices with low dimensions may be convenient to improve the sensor sensitivity and make the sensor operation more efficient.