Nanometer resolution piezoresponse force microscopy to study deep submicron ferroelectric and ferroelastic domains

Understanding ferroelectricity at the deep submicron regime is desirable in utilizing it for next generation nonvolatile memory devices, medical imaging systems, and rf filters. Here we show how piezoresponse force microscopy can be enhanced (1 nm resolution). Using this method, we have investigated ferroelectric and ferroelastic domains at the deep submicron regime in polycrystalline lead zirconium titanate thin films. We demonstrate that in the clamped films, periodic pairs of 90 degrees domains are stable even at 10 nm width, challenging recent predictions of minimum domain size, and suggesting ferroelectricity for high-density storage devices (>= 10 Tbyte/in(2)).