Surface Chemistry

From discovering new and improved ways to access our natural resources to exploring how fuel cells can be better fabricated, these developments are certain to have a lasting effect on industry thanks to advances at NINT’s surface chemistry laboratories.

The space

Here, researchers have access to our state-of-the-art X-RAY Diffraction and Scanning Probe Microscopy equipment.

X-RAY Diffraction

X-ray diffraction (XRD) is used to determine structural information of materials at the atomic scale (crystal lattices), nanoscale (molecules) and up to the micrometre range (such as thin films), from fluids, to powders, layered films, and perfect crystals.

Model

  • Bruker D8 Discover

X-Ray Source

  • Sealed Cu tube

Detection Systems:

  • Position Sensitive area detector: Bruker HiStar GADDS system
  • Linear Detection: Bruker scintillator (NaI)

Goniometer and Sample Stage

  • ¼ cradle Eulerian stage with programmed motions for X, Y, Z, 2θ, Omega, Chi and Phi rotations.

Capabilities and Applications

  • Grazing Incidence Diffraction (GID) and X-ray Reflectometry for determining layer properties such as thickness, density or roughness in Thin Film studies
  • High resolution XRD: lattice spacings and mismatches, layer thicknesses as well as lattice defects and stacking faults.
  • Phase analysis.
  • Texture and Residual stress analysis.
  • Conventional methods of Powder Diffraction for crystallography.
  • Small Angle X-ray Scattering (SAXS).
  • Heating stage: 1200°C (vacuum), 700°C (air).

photo_surface_saxs

Small Angle X-ray Scattering (SAXS) instrument

photo_surface_radiation

Radiation protection housing and X-ray console (computer control station not shown)

photo_surface_cradle

The Eulerian ¼ cradle (center) with circular sample stage. Area detector on 2θ arm (left) and x-ray source (upper right).

Scanning Probe Microscopy

photo_surface_scanning_probe

Scanning Probe Microscopy (SPM) provides extraordinary atomic scale topographic imaging of surfaces, as well as surface measurements of the mechanical, electrical, magnetic and chemical forces.

These metrology studies include applications to surfaces of a variety of natural and synthetic materials such as film coatings, ceramics, composites, biological membranes, polymers, metals, and semiconductors to investigate surface phenomena such as smoothness/roughness, abrasion, adhesion, friction, corrosion, or lubrication properties.

Images from the atomic scale to 175 µm are attainable from the multimode atomic force microscope in Surfaces Characterization Laboratories at NINT.

Model

  • Digital Instruments NanoScope IV Multimode Atomic Force Microscope.

Modes of Analyses

The above applications are accomplished by one or several of the following modes of operation:

  • Contact, Tapping and Scanning Tunneling modes are used for topographic imaging.
  • The Magnetic Force mode measures variations in magnetic field across the sample surface.
  • The Electrostatic Force Microscopy mode measures electrostatic charges and surface potential distribution properties of the sample surface.
  • Simultaneous Conducting mode (1pA to 1µA) characterizes conductivity variations across medium-to low-conducting and semiconducting materials, such as conductive polymers and nanotubes, while imaging in contact mode.
  • Scanning Capacitance Microscopy measures variations in carrier concentration across the sample surface.

Also available are heating stages to allow measurements at temperatures from 0°C to 250°C.

Scanning column and probe head of the Nanoprobe IV atomic force microscope.