Conduction electron density of states and proton spin-lattice relaxation in the dihydrides of Sc, Y, La, and Lu

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:7064634

Torgeson, D R; Lu, L T; Phua, T T; Barnes, R G; Peterson, D T; Seymour, E F.W.

Measurements of the proton spin-lattice relaxation time T/sub 1/ are frequently utilized as a basis for estimating the electronic density-of-states (d.o.s.) at the Fermi level, N(E/sub F/), and its dependence on hydrogen concentration, alloy composition, etc., in metal hydrides. This follows from the fact that quite generally the Korringa product T/sub 1//sub e/T (where T/sub 1//sub e/ is the electronic contribution to the measured T/sub 1/) is related to N(E/sub F/) by (T/sub 1//sub e/T)/sup -1/2/ proportional to N(E/sub F/). At low temperatures where hydrogen diffusion is negligible, the measured relaxation rate R/sub 1/ = (T/sub 1/)/sup -1/ is expected to be given by R/sub 1/ = R/sub 1//sub e/ + R/sub 1//sub p/ where R/sub 1//sub e/ = (T/sub 1//sub e/)/sup -1/ and R/sub 1//sub p/ is the relaxation rate due to proton spin diffusion to paramagnetic impurity ions present in the metal. The determination of R/sub 1//sub e/ from measured values of R/sub 1/ thus also involves the determination or estimation of R/sub 1//sub p/. As shown recently, the presence of RE impurities at levels as low as 10 parts-per-million (ppM) can produce significant effects. We report determinations of proton T/sub 1//sub e/T in the dihydride phases of Sc, Y, La, and Lu based on samples prepared from the highest purity metals available in the Ames Laboratory and in addition in some cases utilizing the technique of partial deuteration to further suppress the paramagnetic contribution R/sub 1//sub p/.

• Research Organization: Ames Lab., IA (USA); Warwick Univ., Coventry (UK). Dept. of Physics
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 7064634
• Report Number(s): IS-M-480; CONF-8404106-7; ON: DE84014123
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ENERGY LEVELS
ENERGY-LEVEL DENSITY
FERMI LEVEL
HYDRIDES
HYDROGEN COMPOUNDS
LANTHANUM COMPOUNDS
LANTHANUM HYDRIDES
LUTETIUM COMPOUNDS
LUTETIUM HYDRIDES
RARE EARTH COMPOUNDS
RELAXATION
SCANDIUM COMPOUNDS
SCANDIUM HYDRIDES
SPIN-LATTICE RELAXATION
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM HYDRIDES