The effect of humidity on nano-scaled domain switching in LiNbO3 single crystal

This paper deals with the influence of relative humidity on nano-scaled domain switching caused by the electric field of atomic force microscopy (AFM) in a LiNbO3 single crystal. Experimental results show that the switched domain size under AFM tip does not increase monotonously with relative humidity. The domain radius increases slightly in lower relative humidity conditions (< 40%), and decreases dramatically in higher relative humidity conditions (40-99%). The domain is not created under a relative humidity of 99%. Experiments on the AFM force-distance curve prove that there is a water bridge between the tip and the sample surface, whose size increases with the rise of humidity. The influence of water bridges on the effective electric field acting on the domain switching in the sample is discussed. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3603020]