Hexagonal Close-Packed (HCP) Crystallography, Diffraction, and Indexing Conventions

reportActive / Technical Report | Accesssion Number: AD1115835 | Open PDF

Abstract:

This report details the crystallography and diffraction pattern indexing of hexagonal close-packed (HCP) crystals compared with the more familiar cubic close-packed crystals. HCP films are frequently grown and characterized at the US Army Combat Capabilities Development Command Army Research Laboratory, in particular alloys of gallium nitride, indium nitride, aluminum nitride, and silicon carbide. We discuss the MillerBravais indexing system, which relies on four indices (HKIL), as opposed to the more familiar three-index (hkl) Miller system. Both systems appear in the literature. Visualizing the HCP system and understanding its indexed features are much less intuitive than it is for the cubic system. The purpose of this note is to 1) assist researchers in their understanding of the literature related to HCP alloys and allow them to correctly describe these alloys characteristics in their own work, and 2) serve as a reference for correctly interpreting transmission electron microscopy images and diffraction patterns.

Author(s):
Sarney, Wendy L.
Author Organization(s):
DEVCOM Army Research Laboratory
Funding Organization(s):
Publication Date:
2020 Nov 17
Pagination:
0

Security Markings

RECORD

Collection: TRECMS
Subject Terms
Modernization Areas:
Microelectronics
Communities of Interest:
No COI(s) Identified
Descriptor(s):
compound semiconductors, diffraction, silicon carbide, electron diffraction, crystal structure, crystallography, electron microscopy, military research, aluminum nitrides, gallium nitrides, nitrides, abstracts, chemistry, crystals, elements, microscopy
Keyword(s):
tem (transmission electron microscopy), hcp (Hexagonal Close-Packed), hcp crystals, HCP films, four-index Miller-Bravais indices, HCP alloys, diffraction patterns, three-index Miller indices
Subject Categories:
Physics; Physics
Update Date:
2020 Dec 23