Objectives

A) Type of analysis/characterization possible with the instruments: Atomic Force Microscopy (AFM), Scanning Tunneling Microscopy (STM), Near field Scanning Optical Microscopy (NSOM), Electrical Force microscopy (EFM), Magnetic Force Microscopy (MFM), Lateral Force Microscopy (LFM), AFM and NSOM in liquid cell B) Recent works of significance done with the instrument/facility: Surface topography of various metals, semiconductor, ceramic and polymer samples have been studied. Phase imaging of polymer sample surface has been done successfully. Research workers of different departments and centres of the institute use the laboratory for different surface studies of their samples. Various outside R &D organisations and academic institutions get their samples analysed in this laboratory. C) Type of projects (broad areas) in which the instrument can be useful: * Surface analysis of thin films, low dimensional features and manipulation of matter at nanoscale (Nano indentation, Nanolithography) * Analysis of Electrical and Magnetic properties * Analysis of Biological samples * Surface analysis of polymer materials

People

Prof. Rabibrata  Mukherjee

Facilitator

Chemical Engineering

rabibrata@che.iitkgp.ernet.in

+91-3222-283912

Equipment Details

Scanning Probe Microscope (SPM)/ Atomic force microscope (AFM)

Utility and Working Principal

The AFM consists of a cantilever with a sharp tip (probe) at its end that is used to scan the specimen surface. The cantilever is typically silicon or silicon nitride with a tip radius of curvature on the order of nanometers. When the tip is brought into proximity of a sample surface, forces between the tip and the sample lead to a deflection of the cantilever according to Hooke's law. Depending on the situation, forces that are measured in AFM include mechanical contact force, van der Waals forces, capillary forces, chemical bonding, electrostatic forces, magnetic forces (see magnetic force microscope, MFM), Casimir forces, solvation forces, etc. Along with force, additional quantities may simultaneously be measured through the use of specialized types of probes (see scanning thermal microscopy, scanning joule expansion microscopy, photothermal microspectroscopy, etc.).
The AFM can be operated in a number of modes, depending on the application. In general, possible imaging modes are divided into static (also called contact) modes and a variety of dynamic (non-contact or "tapping") modes where the cantilever is vibrated or oscillated at a given frequency.