As a room temperature multi-ferroic with coexisting anti-ferromagnetic, ferroelectric and ferroelastic orders, BiFeO
3
has been extensively studied to realize magnetoelectric devices that enable manipulation of magnetic ordering by an electric field. Moreover, BiFeO
3
is a promising candidate for ferroelectric memory devices because it has the largest remanent polarization (
P
r
>100 μC cm
−2
) of all ferroelectric materials. For these applications, controlling polarization switching by an electric field plays a crucial role. However, BiFeO
3
has a complex switching behaviour owing to the rhombohedral symmetry: ferroelastic (71
°
, 109
°
) and ferroelectric (180
°
) switching. Furthermore, the polarization is switched through a multi-step process: 180
°
switching occurs through three sequential 71
°
switching steps. By using monodomain BiFeO
3
thin-film heterostructures, we correlated such multi-step switching to the macroscopically observed reliability issues of potential devices such as retention and fatigue. We overcame the retention problem (i.e. elastic back-switching of the 71
°
switched area) using monodomain BiFeO
3
islands. Furthermore, we suppressed the fatigue problem of 180
°
switching, i.e. loss of switchable polarization with switching cycles, using a single 71
°
switching path. Our results provide a framework for exploring a route to reliably control multiple-order parameters coupled to ferroelastic order in other rhombohedral and lower-symmetry materials.
Ferroelectric ground state and polarization-switching path of orthorhombic YMnO3with coexistingE-type and cycloidal spin phases
