Enhancing the thermal stability of switched domains in lithium niobate single-crystal thin films

Domain modulation in LiNbO3 films using litho piezoresponse force microscopy

“…Further, polarization reversal is completed through the dense point poling in area of 5 μm×5 μm. All results indicate the feasibility and stability of this method to domain reversal, which is superior to the existed repeat-poling method [32].…”

“…As both ferroelectric and non-ferroelectric materials exhibit hysteresis behavior in switching spectroscopy PFM results, the observation of such loops alone is not convincing to confirm intrinsic ferroelectric nature [36,37]. To exclude fake ferroelectric response, the phase image of virgin sample was captured via piezoresponse force microscopy (PFM) in Dual-AC Resonance Tracking mode (DART) with AC sinusoidal signal of 1 V, in which topography influence on domain pattern has been minimized [11,32]. The DC bias is applied to tip and then arrays of poling region are obtained as shown in figures 3, S1 and S2 are available online at stacks.…”

“…The Pt interlayer with thickness of 100 nm was introduced to serve as bottom electrode and heterostructure consisting of LN/Pt/SiO 2 /LN was finally obtained. Then LN films layer were polished down to 700 nm by chemical mechanical polishing (CMP) technology, and the surface roughness was controlled within optical quality [32].…”

“…After polishing of films, the topography was characterized using atomic force microscopy (MFP-3D, Asylum Research, USA), piezoelectric property and domain reversal were examined with functionality of switching spectroscopy piezoresponse force microscopy (SS-PFM) and litho piezoresponse force microscopy [11,32]. The measurements were conducted using a conductive probe (SCM-PIT-75, Nanoworld) combined with Pt/Ir-coated tip radius of ∼25 nm, elastic coefficient of about 2.8 N m −1 , and resonance frequency of 75 kHz.…”

“…In most cases, tip-induced local polarization reversal lead to the formation of isolated domains, which nucleates with regular hexagonal or circular pattern [27,29]. Still in some special cases, domains switch abnormally in poling center and along the path of grounded tip after removement of external electric fields [29,31,32].…”