Magnetoelectric effect within individual domains and domain walls in yttrium iron garnet Y₃Fe₅O₁₂

Abstract

Quadratic magnetoelectric (ME) effect in the single crystals of Y₃Fe₅O₁₂, and Y₃Fe_5-xGa_xO₁₂ (x = 0.6) was studied within individual magnetic domains and in the regions of crystal containing individual domain wall. In longitudinal geometry H||n, where H is the magnetic field, n is the normal to the sample surface, the ME effect in YIG within domains is characterized by a value β^me = 1.0·10⁻¹⁸ Wb/V² in the regime of domain wall movement. In the regime of magnetization rotation the value of β^me is drastically smaller β^me = 1.2·10⁻¹⁹ Wb/V². In transversal geometry H⊥ME effect shows the singularity at H = H_a , where H_a is the anisotropy field. The ME effect concerned with an electric field induced domain wall motion was observed in the presence of magnetic field. The magnitude of effect depends on the value of magnetic field, the curvature of the wall and the position of the wall in the crystal. The theoretical analysis based on the assumption of magnetic anisotropy modification in an electric field is given.

Key Words:

• Iron garnet
• domain
• magnetoelectric
• anisotropy.