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Investigation of magnetoresistive properties of fexible lanthanium perovskites structures

Nanostructured films of lanthanum perovskites, such as manganites or cobaltites, exhibit a wide variety of electrical and magnetic properties - changing their chemical composition and growing conditions (substrate temperature, growth rate, etc.) can significantly alter their physical properties such as resistivity and magnetoresistance. Nanostructured manganite-cobaltite films have recently been intensively investigated for application in magnetic field sensors. It has been found that nanostructured films of manganites exhibiting Colossal Magnetoresistance  (CMR) effect can be used for development of high and even megagauss B-scalar magnetic field sensors that measure magnetic field independently of its direction. However, most applications require the measurement of weak (<0.5 T) and medium (<20 T) magnetic fields. In this case, the magnitude of the magnetoresistance (MR) and its anisotropy (MRA) play a significant role. Therefore, ways to increase the sensitivity of such films to the magnetic field are of great importance. Meanwhile, giant (GMR), anisotropic (AMR), or tunnel (TMR) magnetoresistive structures can only measure weak (up to 1 T or less) magnetic fields. Medium magnetic fields are becoming increasingly important in today's industry. In addition, magnetic field sensors formed on flexible substrates are very important. The magnetoresistive properties of nanostructured manganite-cobaltite films formed on flexible substrates have not been studied so far. Therefore, this work will aim to investigate the magnetoresistive characteristics of manganite-cobaltite structures formed on flexible substrates in weak (<0.5 T) and medium (0.5-10 T) magnetic fields, to identify predominant charge transfer mechanisms and to propose novel magnetic field sensors based on these structures, which are highly sensitive over a wide range of magnetic fields.
 
For more information, please contact the theme supervisor N. Žurauskienė.