Accession Number : AD0894817

Title :   Single Crystal Dielectrics for High Energy Storage.

Descriptive Note : Final technical rept. 15 Oct 70-26 Feb 72,

Corporate Author : RAYTHEON CO WALTHAM MA RESEARCH DIV

Personal Author(s) : Readey, Dennis W. ; Schapira, Morey R.

Report Date : MAY 1972

Pagination or Media Count : 117

Abstract : The purpose of this program was to evaluate commercially-available single crystals as potential dielectrics for high-energy-density-storage capacitors. In keeping with the intended application, an extensive series of property measurements consisting of primarily AC dielectric breakdown, dielectric constant, loss tangent, and DC volume resistivity on nomially five mil thick single crystals was carried out. Also included were measurements on two polycrystalline materials: chemical-vapor-deposited boron nitride and conventional-ceramic processed cadmium titanate. The results suggest that thin mica is the best material from a number of considerations for the intended application. The report consists of an initial discussion of the material parameters important for high-energy-density electrical storage. Particular emphasis is given to enumerating and discussing the various factors affecting dielectric breakdown and breakdown measurements since dielectric strength is the key factor to high-energy-storage capacity. A description of dielectric breakdown, dielectric constant and loss tangent, and DC volume resistivity measurement apparatus are given. Sample preparation and handling is discussed and an extensive tabulation of data measured along with other experimental observations is given. Finally, literature data on breakdown of single crystals is tabulated and compared to the results obtained in this study. The present investigation represents one of the most comprehensive studies or surveys of dielectric breakdown and energy storage of single crystals to date and this report should serve as a reference to those in the field.

Descriptors :   (*DIELECTRICS, SINGLE CRYSTALS), (*CAPACITORS, DIELECTRICS), DISSIPATION FACTOR, VOLTAGE, DIELECTRIC PROPERTIES, ELECTRICAL RESISTANCE, MICA, POROSITY, DISLOCATIONS, VAPOR PLATING, SHEETS, X RAYS, CRYSTAL DEFECTS, ELECTROCHEMISTRY, ELECTRODES, FILMS, ENERGY, STORAGE, FAILURE(ELECTRONICS).

Subject Categories : Electrical and Electronic Equipment
      Miscellaneous Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE