ON THIN ICE:

Sandia researchers use a scanning tunneling microscope (STM) to study ice-film morphology in greater detail than ever before. At 140 kelvins (–208 degrees Fahrenheit or –133 Celsius), water deposited on a platinum surface forms irregular one-molecule-thick patches....[More]

ON THIN ICE:

Sandia researchers use a scanning tunneling microscope (STM) to study ice-film morphology in greater detail than ever before. At 140 kelvins (–208 degrees Fahrenheit or –133 Celsius), water deposited on a platinum surface forms irregular one-molecule-thick patches. In all STM images the higher surface regions appear brighter, while the darker portions indicate depressions. The slightly triangular feature in the center, for example, is a one-atom-deep depression in the platinum.  [Less] [Link to this slide]

Courtesy of Sandia National Laboratories

ONE ATOM DEEP:

All solid surfaces are uneven at the microscopic level. When more water is deposited the irregular ice patches from the first slide expand and merge until the one-molecule layer covers the entire surface....[More]

ONE ATOM DEEP:

All solid surfaces are uneven at the microscopic level. When more water is deposited the irregular ice patches from the first slide expand and merge until the one-molecule layer covers the entire surface. The irregularly shaped depression is the last remaining patch of bare platinum that still hasn’t been overgrown by the ice layer. The dark, hexagonal depression above is an ice-covered one-atom deep dip in the platinum surface.  [Less] [Link to this slide]

Courtesy of Sandia National Laboratories

HEXAGONS:

Once ice (from the condensation) completely covers the platinum surface, three-dimensional, hexagon-shaped mini crystals start to form. These two- to three-nanometer-thick crystals are surrounded by the original ice film layer, which now appears black....[More]

HEXAGONS:

Once ice (from the condensation) completely covers the platinum surface, three-dimensional, hexagon-shaped mini crystals start to form. These two- to three-nanometer-thick crystals are surrounded by the original ice film layer, which now appears black.  [Less] [Link to this slide]

Courtesy of Sandia National Laboratories

MINI MAZE:

More condensation freezes and the average thickness of the ice grows to 1.5 nanometers. All of the mini crystals merge into a labyrinthine pattern, with the dark channels indicating the original ice film layer....[More]

MINI MAZE:

More condensation freezes and the average thickness of the ice grows to 1.5 nanometers. All of the mini crystals merge into a labyrinthine pattern, with the dark channels indicating the original ice film layer.  [Less] [Link to this slide]

Courtesy of Sandia National Laboratories

ATOMIC TERRACE: At a total film thickness of four nanometers, most channels are filled in and atomically flat terraces up to 200 nanometers wide form. [Link to this slide]
Courtesy of Sandia National Laboratories

ICE NINE: The entire platinum sample is covered when the ice thickens to nine nanometers. Just a few pinholes reaching down to the original wetting layer remain. [Link to this slide]
Courtesy of Sandia National Laboratories