Alternating electric force microscopy: Static electric field gradient imaging in an air atmosphere for Ba_(0.7)Sr_(0.3)TiO_3 ferroelectric thin film

摘要

An alternating electric force microscopy (A-EFM) technique, which is effective for the imaging of static electric field gradient in an air atmosphere, is proposed by using our developed alternating force microscopy. A-EFM uses a frequency modulation of a mechanically oscillating conductive tip, which is induced by applying off-resonant AC voltage to the tip. The AC voltage generates off-resonant alternating electric force at the tip. A-EFM detects static electric field gradient with the field polarity from a sample without involving surface forces by using a lock-in detection technique. For a Ba_(0.7_Sr_(0.3)TiO_3 ferroelectric thin film, A-EFM clearly imaged the static electric field gradient with field polarity and the boundary of electric domain in an air atmosphere.