Contribution to the theory of high-temperature vaporization and electron emission: Application to neodymium hexaboride and lanthanum hexaboride

Journal Article · Wed Apr 01 00:00:00 EST 1981 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.329037· OSTI ID:6401369

Storms, E K

The thermionic emission properties of polycrystalline NdB/sub 6/ have been determined as a function of surface composition throughout its single-phase region. the equation log I = 1.673-15637/T+2 log T-0.0042 T/)exp(0.07X/(X-6))+1) describes the relationship between emitted current flux I (A/cm/sup 2/), temperature T (K), and surface composition X (B/Nd) between 1200 and 1600 K. The effective work function at 1500 K is 3.22 eV for NdB/sub 6.0/ and 4.04 eV for NdB/sub 8.0/. Previous measurements of the LaB/sub 6/ phase were fit by the equation log I = 2.533-15330/T+2 log T-0.5T exp(-0.11X/(X-6)). This information was used to determine the density of states for the two hexaborides and make predictions about the behavior of various ternary systems.

• Research Organization: Los Alamos Scientific Laboratory, Los Alamos, New Mexico 87545
• DOE Contract Number: W-7405-ENG. 36
• OSTI ID: 6401369
• Journal Information: J. Appl. Phys.; (United States), Vol. 52:4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NEODYMIUM BORIDES
ELECTRON EMISSION
EVAPORATION
COMPARATIVE EVALUATIONS
ENERGY-LEVEL DENSITY
EQUATIONS
MATHEMATICAL MODELS
POLYCRYSTALS
QUANTITY RATIO
SURFACES
TEMPERATURE DEPENDENCE
THEORETICAL DATA
THERMIONIC EMISSION
VERY HIGH TEMPERATURE
WORK FUNCTIONS
BORIDES
BORON COMPOUNDS
CRYSTALS
DATA
EMISSION
FUNCTIONS
INFORMATION
NEODYMIUM COMPOUNDS
NUMERICAL DATA
PHASE TRANSFORMATIONS
RARE EARTH COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties