Electrical and magneto-transport properties of ferromagnet/ superconductor/ferromagnet based heterostructure

摘要

La_(0.7)Sr_(0.3)MnO_3/YBa_2Cu_3O_7/La_(0.7)Sr_(0.3)MnO_3 (LSMO/YBCO/LSMO) heterostructures were prepared by pulsed laser deposition technique. The resistivity–temperature (ρ–T) variation and magnetoresistance effects of these heterostructures have been studied and are found to be dependent on the thickness of superconducting spacer layer. We have observed that metal–insulator (T_(MI)) transition get suppressed with increase in thickness of the spacer layer. The maximum magnetoresistance ratio ~70% at 266 K and ~65% at 254 K temperature are observed for 50 nm and 100 nm spacer layers respectively. In LSMO(200 nm)/YBCO(50 nm)/LSMO(200 nm) specimen the temperature coefficient of resistance (TCR) is ~6.63% K~(-1) which can be useful for bolometric performances and temperature sensors.