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

Abstract

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.

Large magnetodielectric response of PST/LSMO/LCMO film over a wide temperature range

“…Assembling LSMO and LCMO together is expected to obtain large MR and low r over a wider temperature range near room temperature. Pb 0.6 Sr 0.4 TiO 3 (PST) was chosen as dielectric layer for its excellent dielectric properties, whose lattice structure is simple and has only one phase transition, that is the ferroelectric-paraelectric phase transition, and the T c is far above 400 K. [27][28][29] Compared with pulsed laser deposition and sputtering, CSD has the advantages of excellent chemical homogeneity, easy control of stoichiometry, and suitable for large area. [30][31][32] Si wafer was chosen as substrate because the Si wafer is one of the main micro-electronic materials, which is essential for future commercial applications.…”