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in creator/contributor: "Rothman, S.J."

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Oxygen diffusion in cuprate superconductors

Superconducting properties of the cuprate superconductors depend on the oxygen content of the material; the diffusion of oxygen is thus an important process in the fabrication and application of these materials. This article reviews studies of the diffusion of oxygen in La{sub 2}{sub {minus}}{sub {times}}Sr{sub {times}}CuO{sub 4}, YBa{sub 2}Cu{sub 3}O{sub 7}{sub {minus}}{delta}, YBa{sub 2}Cu{sub 4}O{sub 8}, and the Bi{sub 2}Sr{sub 2}Ca{sub n}{sub {minus}}{sub 1}Cu{sub n}O{sub 2}{sub +}{sub 4} (… more

Date: January 1, 1995

Creator: Routbort, J. L. & Rothman, S. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Oxygen diffusion in high- Tc superconductors

The cuprate superconductors are fascinating not only because of their technical promise, but also because of their structures, especially the anisotropy of the crystal lattice. There are some structural similarities among these compounds, but also significant differences. Measurements of the oxygen tracer diffusion coefficients have been carried out as a function of temperature, oxygen partial pressure, crystal orientation, and doping in the La-Sr-Cu-0, Y-Ba-Cu-0, and Bi-Sr-Ca-Cu-0 systems. The… more

Date: July 1, 1992

Creator: Rothman, S. J. & Routbort, J. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Oxygen diffusion in high-{Tc} superconductors

Date: July 1, 1992

Creator: Rothman, S. J. & Routbort, J. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Anisotropy of oxygen tracer diffusion in YBa sub 2 Cu sub 3 O sub 7-. delta. single crystals

The crystal structure of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} strongly suggests that the diffusion of oxygen in this material will be highly anisotropic, with diffusion in the ab plane being much faster than diffusion parallel to the c axis, and this has been assumed in most analyses of diffusion in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}. The present data confirm this hypothesis; the diffusion coefficient in the ab plane is several orders of magnitude greater than the diffusion coefficient along th… more

Date: September 1, 1989

Creator: Rothman, S. J.; Routbort, J. L.; Liu, J.-Z.; Downey, J. W.; Thompson, L. J.; Fang, Y. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Diffusion studies in amorphous NiZr alloys

Tracer impurity and self diffusion measurements have been made on amorphous (a-) NiZr alloys using radioactive tracer, Secondary Ion Mass Spectrometry and Rutherford backscattering techniques. The temperature dependence of diffusion in a-NiZr can be represented in the form D = D/sub 0/exp(-Q/kT), with no structural relaxation effects being observed. The mobility of an atom in a-NiZr increased dramatically with decreasing atomic radius of the diffusing atom and also with decreasing Ni content fo… more

Date: June 1, 1987

Creator: Hahn, H.; Averback, R. S.; Hoshino, K. & Rothman, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Tracer diffusion of /sup 60/Co and /sup 63/Ni in amorphous NiZr alloy

Tracer diffusion of /sup 60/Co and /sup 63/Ni in equiatomic amorphous NiZr alloy in the temperature range between 486 and 641/sup 0/K can be described by: D/sub Co/sup */ = 3.7 x 10/sup -7/ exp(-(135 +- 14) kJ mole/sup -1//RT) m/sup 2//sec and D/sub Ni//sup */ = 1.7 x 10/sup -7/ exp(-(140 +- 9) kJ mole/sup -1//RT) m/sup 2//sec. The values of D/sub Ni//sup */ are in reasonable agreement with those measured by the Rutherford backscattering technique. The measured diffusivities were independent of… more

Date: January 1, 1987

Creator: Hoshino, K.; Averback, R. S.; Hahn, H. & Rothman, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Radiation-enhanced diffusion in metals and alloys

Some phenomena that involves diffusion during irradiation include fission-product redistribution in reactor fuels, defect clustering in CTR walls or fast-reactor cladding, smearing-out of gradients in ion-implanted semiconductors, and microstructure development in a HVEM. This paper is a review of the basics of radiation-enhanced diffusion (REM). The present status of REM today is somewhat the same as diffusion in the 1940's, and recommendations are made for further work. 105 references. (DLC)

Date: January 1, 1975

Creator: Lam, N. Q. & Rothman, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effects of proton bombardment on self-diffusion in silver: a preliminary report

No Description Available.

Date: January 1, 1974

Creator: Lam, N. Q.; Rothman, S. J.; Merkle, K. L.; Nowicki, L. J. & Dever, D. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The Diffusion of Iron and Chromium in Beta Uranium

This note presents the results of some measurements of the diffusion of iron and chromium in beta uranium carried out in connection with studies of the diffusion of these tracers in gamma uranium

Date: unknown

Creator: Rothman, S. J. (Steven J.); Peterson, N. L. & Moore, S. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The Diffusion of Chromium in Gamma Uranium. Partial Report-Metallurgy Program 4.1.27

The diffusion of tracer amounts of chromium in gamma uranium was studied by the radioactive tracer-sectioning method. The temperature dependence of the diffusion coefficient D is given by D = 1.98 x 10/sup -3/ exp(--2l,800/RT)cm/sup 2// sec, in poor agreement with the data of Mosse, Levy, and Adda. Possible reasons for the discrepancy are discussed, and it is concluded that the present data are to be preferred as a basis for theoretical studies of the diffusion of tracers in gamma uranium. The … more

Date: June 1, 1961

Creator: Rothman, S. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Diffusion in Uranium, Its Alloys, and Compounds

ABS>A review of laboratory diffusion studies on uranium and its compounds and alloys is presented. Included are results and analysis of studies on diffusion in single-phase and in multiphase U alloys, diffusion of gases in U, and diffusion in UO/sub 2/. (J.R.D.)

Date: May 1, 1961

Creator: Rothman, S. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Self-Diffusion in Beta Uranium. Partial Report--Metallurgy Division Program 4.1.2

The self-diffusion coefficient of U decreased from 3 x 10/sup -9/ cm/sup 2//sec at 785 deg C to 2.1 x 10/sup -11/ cm/sup 2//sec at 760 deg C. At temperatares high in the beta phase, the plots of log C vs. X/sup 2/ are curved, indicating that self-diffusion in beta U does not take place by isotropic volume diffusion alone. (auth)

Date: July 1, 1960

Creator: Rothman, S. J.; Gray, J., Jr.; Hughes, J. P. & Harkness, A. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The Diffusion of Gold in Gamma Uranium

The diffusion coefficient of tracer amounts of Au/sup 198/ in gamma U is described by an Arrhenius-type equation: D = 4.86 x 10 cm/sup -3/sec exp(-30,400 cal/mol/RT). The values of D/sub 0/ and the activation energy are close to those for self-diffusion in gamma U, indicating that the low activation energy for self- diffusion is due to a general weakness of the lattice rather than to easy compressibility of the U atom. (auth)

Date: May 1, 1960

Creator: Rothman, S. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Self-Diffusion in Gamma Uranium

The self-diffusion coefficient or uranium was measured at four temperatures in the gamma phase. The data are fitted by an Arrhenius-tyoe equation D = 2.33 x well with previously reported results. The value of D/sub o/ is lower than that predicted by Zener's theory, and the activation energy is much less than the value expected from various empirical codelations. (auth)

Date: July 1, 1959

Creator: Rothman, S. J.; Lloyd, L. T.; Weil, R. & Harkness, A. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department