IMF2017

Piezoresponse Force Microscopy (PFM) has emerged as a powerful tool for experimental investigations of ferroelectric materials. In the imaging mode, PFM allows visualization of static domain structures with nanometer spatial resolution. Application of a sufficiently large voltage through a conductive scanning probe microscopy (SPM) tip can induce local polarization switching and can be extended for creation of tailored domain structures and ferroelectric data storage. Finally, acquisition of the piezoresponse signals during polarization reversal allows measurement of local hysteresis loops, which can be used for characterization of the switching process in the nanoscale area in the vicinity of the tip. The broad application of PFM for probing domain structures and polarization reversal in ferroelectrics demands deep understanding of the basic mechanisms involved. PFN (Pb(Fe_0.5Nb_0.5)O₃) thin films were grown by optimized pulsed laser deposition (PLD) . The highly c-axis oriented growth containing only (00l) diffraction peaks of PFN films along with in plane epitaxial relationship were confirmed by high resolution X-ray diffraction measurements. PFN thin films possess well saturated ferroelectric hystersis and weak ferromagnetism at room temperature. The existence of ferroelctricity at nanoscale is confirmed by band excitation PFM. The ferroelectric phase transition is also probed by the temperature dependence of piezoresponse studies. In addition to the temperature dependence of piezoresponse studies the phase transition is also confirmed by temperature dependent dielectric spectra. Detailed studies on effect of temperature on coercive field, imprint, switchable polarization, nucleation bias of PFN will be discussed in the meeting.