Major Equipment:

Atomic force microscopes:

DI Dimension-3000 AFM

DI Dimension-3100 AFM

DI Nanoscope-IV Multimode AFM

Optical microscopes:

Olympus Optical Microscope

Leica Confocal Optical Microscope

Ellipsometers:

Sopra Variable Angle Spectroscopic Ellipsometer

Profilometers:

Veeco Dektak Stylus Profilometer

Filmetrics Optical Profilometer

X-Ray Scattering Equipment:

Molecular Metrology SAXS

Recharge Rates:

Training: Please contact Prof. Sekar T. Dhanasekaran for training.

Atomic Force Microscopes

DI Dimension-3000 and Dimension-3100 AFM The Dimension model AFM uses tip scanning to obtain topographic and phase imaging of the surface. This method allows samples up to 200 mm in diameter to be scanned. Apart from polymer samples that are mainly studied in our lab, this equipment can image semiconductor wafers, lithography masks, magnetic media, CDs/DVDs, biomaterials and other materials with sub-nanometer resolution in the vertical (z) dimension. The maximum scan area in the x,y dimension is 100 μm2. In addition accessories are available to carry out STM, MFM and imaging under liquid.

DI Nanoscope-IV Multimode AFM The Multimode model AFM uses sample scanning to obtain topographic and phase imaging of the surface and hence the sample size is limited to ~ 1 cm2. This equipment can image samples using the Contact mode, Tapping mode and Imaging under liquid. In addition this equipment is capable of imaging under variable temperature from room temperature up to 250°C.

Optical Microscopes

Olympus Optical Microscope This Olympus model optical microscope is routinely used to study Polymer film morphology and structural changes under various temperatures. It is equipped with tungsten lamp to image in reflection/transmission mode and a mercury lamp for fluorescence imaging. It has two digital cameras and an image capture card interfaced to a computer. It has accessories to image in dark field contrast, interference contrast, polarized light contrast and a programmable hot stage to study at various temperatures.

Leica Confocal Optical Microscope The confocal microscope is an excellent optical imaging tool pushing the resolution limits of the optics. Our system is a Leica DM-IRBE. It has many advanced features like precision motorized Z-drive, two lamps (halogen and a mercury lamp) coupled with multi laser excitation and dual photomultiplier detection. It is also equipped with Narishige micromanipulator and microinjection tools for cell and vesicle manipulation.

Ellipsometers

Sopra Variable Angle Spectroscopic Ellipsometer The variable angle spectroscopic ellipsometer (VASE) is an excellent tool to measure thin film thickness and its refractive index. The instrument shines linearly polarized light on the sample surface and the ellipticity of the reflected light from the sample surface is analyzed for the s-polarized and p-polarized components of the light. Since it measures the ratio of the s and p polarized light the data is very accurate. The data is measured over the entire wavelength range and compared to a mathematically generated model to obtain film thickness and refractive index etc. This instrument can work in the visible range of the spectrum (250-850 nm) as well as in the NIR (850-2500 nm) region. Since it is spectroscopic ellipsometry multi layered films could be analyzed accurately.

Profilometers

Veeco Dektak Stylus Profilometer The stylus profilometer uses a diamond tipped stylus to scan across the sample surface and measures the surface topography of thin and thick films. The vertical movements of the stylus is measured and recorded simultaneously during the scanning, which reveals the topographical structure of the surface. The instrument has vertical resolution in nanometers and horizontal resolution as small as twenty nanometers and measures the film thicknesses from 5 nm and over 500 µm.

Filmetrics Optical Profilometer An optical profilometer measures thin film properties using the spectral reflectance technique. Spectral reflectance measures the amount of light reflected from a thin film over a range of wavelengths, with the incident light perpendicular to the sample surface. It can measure the thickness, roughness, and optical constants of a film by measuring how the films interact with light. Optical constants describe how light propagates through and reflects from a material. Once the optical constants are measured they may be related to other material parameters, such as composition and band gap. This method is non-destructive, and requires little or no sample preparation, but has a limitation of measuring only less complex structures. For more detailed measurements, ellipsometry is the most suitable method.

X-Ray Scattering

Molecular Metrology Small Angle X-Ray Scattering Small Angle X-ray Scattering (SAXS) is used to obtain detailed information about electron density distribution and molecular assemblies in the 1-100 nm size range. This equipment uses a high brilliance Rigaku Osmic X-ray source with focusing optics. The sample chamber is a unique design equipped with automatic sample changer and provision for introducing image plate for wide angle X-ray scattering measurements. In addition it is equipped with a variable temperature sample holder. The scattered X-rays are collected with a 2-D wire array detector which is interfaced to the computer.