Strain relaxation in Bi0.9Pb0.1FeO3/SrRuO3/SrTiO3 heterostructures

The magnetic and crystalline properties of Bi0.9Pb0.1FeO3/SrRuO3(100 nm)/SrTiO3 heterostructures with different thickness of Bi0.9Pb0.1FeO3 (80-400 nm) are studied. The heterostructure undergoes a strain relaxation at each interface. Surprisingly, the crystal lattice of the bottom SrRuO3 layer can be manipulated by the top Bi0.9Pb0.1FeO3 layer, with its unit cell volume shrinking for a thicker top Bi0.9Pb0.1FeO3 layer. The magnetic properties of the bottom SrRuO3 layer seem independent of the change of its crystal structure. These extraordinary phenomena can be ascribed to the inter-diffusion of Bi and Pb ions of the top Bi0.9Pb0.1FeO3 layer into the bottom SrRuO3 layer and substrate. (C) 2012 American Institute of Physics. [doi:10.1063/1.3671791]