Accession Number : AD0443487


Title :   INTERSTITIAL COMPOUNDS OF BORON AND TRANSITION METALS. PACKING OF B12 GROUPS IN BORON AND BORIDE STRUCTURES,


Corporate Author : CARBORUNDUM CO NIAGARA FALLS NY


Personal Author(s) : Matkovich, V I ; Giese, R F , Jr ; Economy, J


Report Date : Jul 1964


Pagination or Media Count : 25


Abstract : This study is concerned with the establishment of structural properties common to all borides and modifications of boron which contain B12 polyhedral units. It has been found that all unit cell dimensions in these structures can be derived from simple arrangements of B12 units which can be regarded as large metallic atoms that form interstitial compounds. The B12 units can also group together to form larger units such as the recently reported B84. These are also treated as individual entities. On this basis all the structures have been classified into three simple packing models: (1) cubic closest packing, (2) hexagonal closest packing, and (3) tetragonal closest packing. Occurrence of tetragonal closest packing with 10 closest neighbors is unusual and is discussed in detail. The proposed simple models and their subclassifications lead to a successful interpretation of observed data and should provide a basis for prediction of possible structures of the B12 borides. (Author)


Descriptors :   *BORIDES , CRYSTAL STRUCTURE , BORON , CRYSTAL STRUCTURE , BERYLLIUM COMPOUNDS , CARBON COMPOUNDS , ALUMINUM COMPOUNDS , SYMMETRY(CRYSTALLOGRAPHY) , CRYSTAL DEFECTS , ATOMIC PROPERTIES


Distribution Statement : APPROVED FOR PUBLIC RELEASE