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The knight shift in metals: Liquid arsenic
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ABSTRACTS OF PAPERS TO APPEAR IN
On considère un corps dans lequel les moments magnétiques se groupent en trois sousriseaux, les ions appartenant tin mime sousriseau ayant leurs moments paralliles. On suppose l’anisotropie négligeable. Le calcul fait dans I’approximation du champ moléculaire, montre qu’il peut exister deux sortes de structures: soit une structure colinéaire (ferro ou ferrimagnétique) soit une structure dite ‘en étoile’. On determine les conditions de stabilité de ces différents types de configuration. On étudie enfin l’évolution d’une structure ‘en étoile’ vers Ufl arrangement colinéaire, obligatoire quand la ternpérature croit ainsi que les différents types de variation de l’aimantation des sous-riseaux et de leur résultante générale. Ces deux derniers points sont traités en partie par le calcul algébrique, en partie par le calcul numérique.
a
We are considering a compound in which the magnetic moments are divided into three sublattices, ions belonging to the same sublattice having their moments parallel. Anisotropy is supposed to be negligible. Calculations made in the approximation of molecular field theory, show that two kinds of structure may exist : either a collinear structure (ferro or ferrimagnetic) or a ‘star’ structure. We determine the stability conditions of these various configurations. Finally we study the evolution of a ‘star’ structure to a collinear arrangement which always occurs when temperature increases and also the different types of variation of the sublattice magnetizations and of the net moment. These two latest points are treated partly by algebraic, partly by numerical calculation.
J.
PHYS. CHEM. SOLIDS
Vol. 7, No. 12
function of crystal composition and doping. Even at these temperatures, the diffusion of nickel is very dependent on the composition of the crystal. For the most part the nickel distribution profiles, as determined using radiotracer techniques, cannot be described by a simple solution of the diffusion equation. Except in crystals containing a large concentration of cation vacancies, the nickel distribution profiles are best fit by two overlapping curves, each of which is a solution of the diffusion equation with different values of the diffusion coefficient. Diffusion into crystals containing a large cation vacancy concentration can be described by a simple solution of the diffusion equation. The range of compositions which can be studied at these temperatures is restricted by the retrograde solubility of lead and tellurium in PbTe. (Received 11 March 1969)
18.
THE KNIGHT SHIFT IN METALS: LIQUID ARSENIC D.A. Rigney (The Ohio State University Columbus, Ohio) and J.A. Blodgett (University of Illinois, Urbana, Illinois)
Using high temperature NMR apparatus, we have measured the Knight shift of liquid arsenic. The resulting value of (0.318 ±0.005) % is slightly low when compared with the Knight shifts of other polyvalent metals approximately normalized for period effects. (Received 25 February 1969)
(Received 4 February 1969) 19. 17.
DIFFUSION OF NICKEL INTO LEAD TELLURIDE BETWEEN 200° AND 400°C. T.D. George and J.B. Wagner, Jr. (Department of Materials Science, Northwestern University, Evanston, Illinois)
The diffusion of nickel into lead telluride has been studied between 200° and 400°C as a
MAGNETIC SUSCEPTIBILITY AND EXCHANGE COUPLING IN THE MINERAL ARDENNITE A.N. Thorpe, F.E. Senftle, and G. Donnay (Howard University, U.S. Geological Survey, and Geophysical Laboratory, Carnegie Institution of Washington, Washington, D.C.)
Ardennite, a rare silicate mineral, contains
ABSTRACTS OF PAPERS TO APPEAR IN
On considère un corps dans lequel les moments magnétiques se groupent en trois sousriseaux, les ions appartenant tin mime sousriseau ayant leurs moments paralliles. On suppose l’anisotropie négligeable. Le calcul fait dans I’approximation du champ moléculaire, montre qu’il peut exister deux sortes de structures: soit une structure colinéaire (ferro ou ferrimagnétique) soit une structure dite ‘en étoile’. On determine les conditions de stabilité de ces différents types de configuration. On étudie enfin l’évolution d’une structure ‘en étoile’ vers Ufl arrangement colinéaire, obligatoire quand la ternpérature croit ainsi que les différents types de variation de l’aimantation des sous-riseaux et de leur résultante générale. Ces deux derniers points sont traités en partie par le calcul algébrique, en partie par le calcul numérique.
a
We are considering a compound in which the magnetic moments are divided into three sublattices, ions belonging to the same sublattice having their moments parallel. Anisotropy is supposed to be negligible. Calculations made in the approximation of molecular field theory, show that two kinds of structure may exist : either a collinear structure (ferro or ferrimagnetic) or a ‘star’ structure. We determine the stability conditions of these various configurations. Finally we study the evolution of a ‘star’ structure to a collinear arrangement which always occurs when temperature increases and also the different types of variation of the sublattice magnetizations and of the net moment. These two latest points are treated partly by algebraic, partly by numerical calculation.
J.
PHYS. CHEM. SOLIDS
Vol. 7, No. 12
function of crystal composition and doping. Even at these temperatures, the diffusion of nickel is very dependent on the composition of the crystal. For the most part the nickel distribution profiles, as determined using radiotracer techniques, cannot be described by a simple solution of the diffusion equation. Except in crystals containing a large concentration of cation vacancies, the nickel distribution profiles are best fit by two overlapping curves, each of which is a solution of the diffusion equation with different values of the diffusion coefficient. Diffusion into crystals containing a large cation vacancy concentration can be described by a simple solution of the diffusion equation. The range of compositions which can be studied at these temperatures is restricted by the retrograde solubility of lead and tellurium in PbTe. (Received 11 March 1969)
18.
THE KNIGHT SHIFT IN METALS: LIQUID ARSENIC D.A. Rigney (The Ohio State University Columbus, Ohio) and J.A. Blodgett (University of Illinois, Urbana, Illinois)
Using high temperature NMR apparatus, we have measured the Knight shift of liquid arsenic. The resulting value of (0.318 ±0.005) % is slightly low when compared with the Knight shifts of other polyvalent metals approximately normalized for period effects. (Received 25 February 1969)
(Received 4 February 1969) 19. 17.
DIFFUSION OF NICKEL INTO LEAD TELLURIDE BETWEEN 200° AND 400°C. T.D. George and J.B. Wagner, Jr. (Department of Materials Science, Northwestern University, Evanston, Illinois)
The diffusion of nickel into lead telluride has been studied between 200° and 400°C as a
MAGNETIC SUSCEPTIBILITY AND EXCHANGE COUPLING IN THE MINERAL ARDENNITE A.N. Thorpe, F.E. Senftle, and G. Donnay (Howard University, U.S. Geological Survey, and Geophysical Laboratory, Carnegie Institution of Washington, Washington, D.C.)
Ardennite, a rare silicate mineral, contains