Double perovskite Sr₂FeMoO_6-δ

The main advantages of Sr₂FeMoO_6-δ (SFMO) for their practical application:

• Large values of MR at high T and low fields H;
• High values of Тс=400 - 470 K;
• ~100% spin polarization of conduction electrons;
• A simple crystal structure, and sufficient thermal stability for use in various types of highly sensitive magnetic field sensors.

Structure Sr₂FeMoO_6-δ

In the superstructure ordering cations Fe³⁺ and Mo⁵⁺ alternate in a checkerboard pattern in the tetragonal unit cell I4/m.

Upon cooling the samples SFMO phase transition from Fm3m to I4/m at temperatures around 420 K. In the tetragonal structure [FeO₆] and [MoO₆] octahedra are constantly revolve around the crystallographic axis С.