Characteristic property of magnetic-field controlled sensor on the base of multilayer structures is based on the phenomenon of spin polarization of conduction electrons.

Principle of the functioning of a magnetic field sensor on the base of tunneling magnetoresistance.

		Sr2FeMoO6 magnetic layers
		Al2O3 dielectric layers

For a realization of the spin-depedent tunnelling effect of a charge transfer, Sr₂FeMoO₆ thin films (~200 nm) are used, which are separated with a thin Al₂O₃ dielectric layer (~ 5-7 nm).

Devices based on magnetic tunnel junctions (MTJ) are basic elements of spintronics. In the previous years, MTJ-structures on the base of La_2/3Sr_1/3MnO₃ were realized with tunneling magnetoresistance of more than 1800 % at 4.2 K, but Curie temperature (TC) less than 300 K have made wide practical applications of this material impossible. In this concern many investigations presently are focused on the double perovskite Sr₂FeMoO_6-δ (SFMO) due to both high Curie temperature (T_C > 415 K) and half-metallic nature of its transport properties. Nearly 100 % spin polarization of conductive electrons of this compound is attractive in the light of the potential application to the magnetoelectronic as magnetic memories or sensors.

Schemes for spintronic devices.