What is high index surface?

High index surfaces are those for which one or more of the Miller Indices are relatively large numbers. The most commonly studied surfaces of this type are vicinal surfaces which are cut at a relatively small angle to one of the low index surfaces.

What is a high index facet?

High-index facets, denoted by a set of Miller indices {hkl} with at least one index greater than unity, possess a high density of low-coordinated atoms, steps, edges, and kinks within these structures and serve as more active catalytic sites.

What is the description of crystal?

crystal, any solid material in which the component atoms are arranged in a definite pattern and whose surface regularity reflects its internal symmetry.

What is crystal plane?

Crystal planes are defined as some imaginary planes inside a crystal in which large concentration of atoms are present. Inside the crystal, there exists certain directions along which large concentration of atoms exists. These directions are called crystal directions.

What is mean by Weiss indices?

The Weiss parameters, introduced by Christian Samuel Weiss in 1817, are the ancestors of the Miller indices. They give an approximate indication of a face orientation with respect to the crystallographic axes, and were used as a symbol for the face.

Is diamond A crystal?

Diamond is also a natural crystal. It is formed in deep earth layers by compression of the mineral carbon under very high pressure. Gemstones can be cut and polished into beautiful shapes due to their composition and hardness.

What is Miller and Weiss indices?

Early in the 19th century W.H. Miller developed a system of crystal face notation which has many advantages over Weiss symbols. These symbols, called Miller indices, are simply the reciprocals of Weiss parameters, cleared of fractions, with the letters denoting the axes omitted.

What are the 6 major crystal systems?

There are six basic crystal systems.

• Isometric system.
• Tetragonal system.
• Hexagonal system.
• Orthorhombic system.
• Monoclinic system.
• Triclinic system.

What is the difference between low index and high index facets?

Since low- and high-index planes cut through the same bulk structure, it follows that the low-index planes have a high density of bonds parallel to their plane, but a lower density of unsatisfied bonds between those planes. Relative to them, the high-index facets display surfaces where the atoms are further apart.

What is the high-low index?

The High-Low Index is a breadth indicator based on Record High Percent, which is based on new 52-week highs and new 52-week lows. The Record High Percent equals new highs divided by new highs plus new lows.

What is a low index plane?

In this notation, a low index plane is one where the sum of the three components is small. Since a facet, a surface of a crystal, is a plane, it can also be described with Miller indices.

What does it mean when the high low index is below 50?

Conversely, a stock index is deemed weak (bearish) when the High-Low Index is below 50, which means new lows outnumber new highs. This indicator can move to its extremities and remain near its extremes when the underlying index is in a strong uptrend or downtrend.