CONSTITUTION AND MAGNETIC SUSCEPTIBILITY OF THE VANADIUM-HYDROGEN SYSTEM. MAGNETIC PROPERTIES OF GADOLINIUM, EUROPIUM AND YTTERBIUM HYDRIDES

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1961

OSTI ID:4768592

Zanowick, R L

An x-ray study was made of the structure and phase relations in the vanadium--hydrogen system, and the magnetic susceptibilities of these alloys were also determined. The magnetic behavior of europium, gadoliniurn, and ytterbium hydrides was examined from 4 deg K to room temperature. The hydrogen-metal alloys were prepared by conventional techniques in conventional vacuum systems. A partial phase diagram for the V--H system was determined for alloys containing up to 42 atomic per cent hydrogen and from room temperature to 205 deg C. In much of the composition and temperature ranges studied, the V-H system is composed of two phases. These are a body-centered cubic phase based on the vanadium structure and a body-centered tetragonal phase (c/a approximately 1.1) of nominally V/sub 2/H stoichiometry. The lattice parameter changes in both phases are shown as a function of temperature and hydrogen concentration. Results of magnetic studies of the V-H alloys at room temperature are consistent with the notion that the hydrogen enters the vanadium interstices as protons and the hydrogen electrons join the vanadium conduction band. A magnetic study of a body- centered tetragonal-phase sample shows the alloy exhibiting Pauli paramagnetism from 78 deg K to room temperature. Magnetic studies on gadolinium hydride suggest that the Curie point observed in elemental gadolinium is dependent upon the conduction band electrons for the magnetic interactions to take place. Hydrided gadolinium exhibited no Curie point, but had an effective magnetic moment comparable to that of gadolinium. These results suggest that the hydrogen in the hydrides is anionic being formed by the depopulation of the metal conduction band. Weakly paramagnetic ytterbium exhibits only slight changes on being hydrided. The changes observed in europium on hydriding are quite pronounced, and europium dihydride is strongly ferromagnetic at 20 deg K and lower. Metallic europium is observed to be either weakly ferromagnetic or paramagnetic in the same temperature range. The europium hydride results are still consistent with the formation of the hydride anion with the concurrent depopulation of the metallic conduction band. However, unlike the GdH system, the conduction band is apparently unnecessary for the magnetic interactions to take place in europium. (Dissertation Abstr., 23: No. 3, 1962)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-17-002130
• OSTI ID: 4768592
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALLOYS
CONFIGURATION
CURIE POINT
ELECTRONS
ENERGY LEVELS
EUROPIUM HYDRIDES
FERROMAGNETIC MATERIALS
GADOLINIUM HYDRIDES
HYDROGEN
INTERACTIONS
IONS
LATTICES
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETISM
MEASURED VALUES
METALS
PARAMAGNETISM
PHYSICS
PREPARATION
PROTONS
QUANTITY RATIO
SUSCEPTIBILITY
TEMPERATURE
VACUUM
VANADIUM
X RADIATION
YTTERBIUM HYDRIDES