Nanoscale imaging of elastic and piezoelectric properties of nanocrystalline lead calcium titanate

Modified lead titanate thin films for pyroelectric infrared detectors on gold electrodes

“…Chopra et al [18] also reported high pyroelectric coefficient of PCT film (433 Â 10 À5 C/m 2 K) that was grown by sol-gel method on ITO surface. Others [19,20] also demonstrated high pyroelectric coefficient for PCT film deposited on Pt surface. Instead of depositing lead titanate on Pt electrode we deposited films on gold electrode which in terms reduce cost of fabrication if the film is applied to MEMS sensors or other applications.…”

Modeling the effect of subsurface interface defects on contact stiffness for ultrasonic atomic force microscopy

“…Mapping of elastic properties at the nanoscale has become a significant application of atomic force microscopy ͑AFM͒ in the recent years. Several methods based on low frequency indentation, 1 tapping mode, 2 and AFM at ultrasonic frequencies 3,4 have been proposed and used to image the surface stiffness of various samples in air and in liquids. 5 All of these methods acquire elasticity information through the AFM tip -sample surface contact stiffness, which is usually modeled as a simple spring and is a function of the sample elasticity as well as the geometry and the material of the AFM tip.…”

Imaging elastic property of surfaces at nanoscale using atomic force microscope

“…The first sample is used to demonstrate the UAFM technique to obtain the contrast in elastic constant which will be compared with earlier images reported using AFAM [5][6][7]12] and piezo-mode AFM [5] techniques. The second sample is used to determine semi-quantitatively the local changes in its elastic property on the sample surface and map the image semi-quantitatively using the grey scale.…”

“…Some of the improvised versions using ultrasonic frequencies are: (1) atomic force acoustic microscopy (AFAM) [1][2][3][4][5][6][7][8][9][10][11][12], in which the sample is bonded to an ultrasonic transducer below it, (2) piezo-mode AFM [5], in which an AC electrical signal in ultrasonic range is fed to the conducting tip of the AFM and the sample is either piezo-electric or ferroelectric and (3) ultrasonic AFM (UAFM) [2,6,11,[13][14][15], in which a piezo-electric transducer is attached to the cantilever holder carrying the AFM tip and the cantilever is excited at ultrasonic frequency. It has been recently shown that one can image the distribution of local stiffness on the sample surface using AFAM [5][6][7], UAFM [11] and piezo-mode AFM [5]. In the present study we will show that UAFM can also be used to estimate semiquantitatively the relative changes in local elastic constants on the surface of the sample using the resonance curves.…”