Resistive characteristics of LSMO/LCMO bi-layers and temperature switching effect of magnetoresistance

Ferromagnetic La 0.7 Sr 0.3 MnO 3/ La 0.7 Ca 0.3 MnO 3 ( LSMO / LCMO ) bi-layers of submicron thickness were deposited by magnetron sputtering on SrTiO 3 ( STO ) and Al 2 O 3 ( ALO ) substrates and temperature dependence of their resistances were investigated. The samples grown on ALO substrates demonstrated lower metal–insulator transition temperatures and higher resistances. The maximum magnetoresistance (MR) of bi-layer grown on STO substrate reached -56% at 184.6 K and magnetic field of 1 T. At temperatures below 150 K a "switching" of MR from negative to positive values (+ 1.7% at 110 K) and a hysteretic behavior of the resistance at low magnetic fields were observed as well.