Accession Number : AD0713554

Title :   DIRECT SOLUTION OF COMPLEX CRYSTAL STRUCTURES BY ELECTRON MICROSCOPY,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J INST FOR EXPLORATORY RESEARCH

Personal Author(s) : Kohn,Jack A. ; Cook,Charles F. , Jr. ; Eckart,Donald W.

Report Date : 1970

Pagination or Media Count : 14

Abstract : Hexagonal ferrites, complex ferrimagnetic oxides having exploitable microwave/millimeter-wave properties, form structures too large and complex for solution by classical diffraction techniques. Determination of crystal structures, however, is essential for a structural understanding of properties and for attaining the ultimate objective of tailor-made materials in thi frequency range. The procedure described herein uses high-resolution replica electron microscopy to 'read out' structural stacking sequences 'encoded' onto hexagonal ferrite crystal surfaces by hydrochloric and, particularly, nitric acid etching. The method readily permits the direct solution of such crystal structures, including materials with larger unit cells than in any known inorganic substances. (Author)

Descriptors :   (*ETCHED CRYSTALS, *ELECTRON MICROSCOPY), (*FERRITES, *CRYSTAL STRUCTURE), ETCHING, TEST METHODS, MICROWAVE EQUIPMENT

Subject Categories : Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE