GEORGIA INST OF TECH ATLANTA SCHOOL OF CERAMIC ENGINEERING
Research was initiated to understand and control the parameters leading to the successful growth of oxide-metal composites and to evaluate the electron emission performance of these structures. Numerous oxides, binary oxide compounds and oxide mixtures have been tested to determine their suitability for induction melting using an rf frequency of 27 mhz. Procedures employing scanning electron microscopy and x-ray diffraction have been developed to characterize oxide-metal composite samples. Metallic fiber morphology has been related to growth direction. A theoretical analysis of expected electron field emission from the array of metallic pins formed during composite growth has been performed using pin diameter, pin spacing, applied voltage and interelectrode spacing as variables. A preliminary description of the solidification behavior of oxide-metal systems is proposed, based on a tentative phase diagram, different oxide-metal ratios and variable growth rates. A diode assembly for field emission testing has been constructed, and the initial field emission testing of an oxide-metal composite sample is described.
Semi-annual technical rept. no. 1, 1 Jul-31 Dec 1970