Structural, magnetic, and ferroelectric properties of T-like cobalt-doped BiFeO ₃ thin films

We present a comprehensive study of the physical properties of epitaxial cobalt-doped BiFeO₃ films ∼50 nm thick grown on (001) LaAlO₃ substrates. X-ray diffraction and magnetic characterization demonstrate high quality purely tetragonal-like (T′) phase films with no parasitic impurities. Remarkably, the step-and-terrace film surface morphology can be fully recovered following a local electric-field-induced rhombohedral-like to T′ phase transformation. Local switching spectroscopy experiments confirm the ferroelectric switching to follow previously reported transition pathways. Critically, we show unequivocal evidence for conduction at domain walls between polarization variants in T′-like BFO, making this material system an attractive candidate for domain wall-based nanoelectronics.