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

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.

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Document Details

Document Type
Technical Report
Publication Date
Nov 17, 2020
Accession Number
AD1115835

Entities

People

  • Wendy L. Sarney

Organizations

  • United States Army Research Laboratory

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Aluminum Nitrides
  • Chemistry
  • Compound Semiconductors
  • Crystal Structure
  • Crystallography
  • Crystals
  • Diffraction
  • Electron Diffraction
  • Electron Microscopy
  • Electrons
  • Elements
  • Gallium
  • Gallium Nitrides
  • Materials
  • Microscopy
  • Military Research
  • Nitrides
  • Semiconductors
  • Silicon Carbide
  • Transmission Electron Microscopy

Readers

  • Artificial Intelligence
  • Materials Science and Engineering.
  • Semiconductor Device Technology

Technology Areas

  • Microelectronics
  • Microelectronics - Microelectromechanical Systems