Bismuth-based-layer-structured ferroelectric films have been formed epitaxially on Nb-doped SrTiO_3 substrates by pulsed laser deposition (PLD). These films show an atomically smooth surface with a wide terrace of 100 nm～200 nm, as observed by atomic force microscopy (AFM) which is ideal for measuring such properties. Thin films of (Bi_(0.7), Ba_(0.3) (Fe_(0.7), Ti_(0.3))O_3 exhibit both ferroelectric and ferromagnetic (weak ferromagnetism) properties at room temperature. In these samples, a size effect is discussed at the same time.
展开▼
