Strain-Induced Ferromagnetism in Antiferromagnetic LuMnO3 Thin Films

Diagram of the processes in the LuMnO3 layers studied. The layer is highly strained close to the substrate, which leads to a ferromagnetic (FM) order there. As the distance grows, the strain decreases so that two antiferromagnetic (AFM) orders appear: the spin spirals and the E-type, where two spins point in one direction and the next two in the other.

Abstract:

Single phase and strained LuMnO3 thin films are discovered to display coexisting ferromagnetic and antiferromagnetic orders. A large moment ferromagnetism (≈1μB), which is absent in bulk samples, is shown to display a magnetic moment distribution that is peaked at the highly strained substrate-film interface. We further show that the strain-induced ferromagnetism and the antiferromagnetic order are coupled via an exchange field, therefore demonstrating strained rare-earth manganite thin films as promising candidate systems for new multifunctional devices.