Browsing by Author "COEY, JOHN MICHAEL DAVID"

Now showing items 1-20 of 102

    • 1/f noise in the half-metallic oxides CrO2, Fe3O4, and La2/3Sr1/3MnO3 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 1999)
      The excess low-frequency (1/f) electrical noise of three representative half-metallic oxides, CrO2, Fe3O4, and La2/3Sr1/3MnO3, has been studied as a function of the temperature (5?300 K) and a magnetic field (up to 12 T). ...

    • Atomic coordination and the distribution of electric field gradients in amorphous solids 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 1981)
      The observation of nuclear quadrupole interactions in amorphous solids provides a unique possibility of obtaining information about the angular distribution of local ionic coordinations, complementary to the information ...

    • Charge dynamics in the half-metallic ferromagnet CrO2 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 1999)
      Infrared spectroscopy is used to investigate the electronic structure and charge carrier relaxation in crystalline films of CrO2 which is the simplest of all half-metallic ferromagnets. Chromium dioxide is a bad metal at ...

    • Coercivity mechanism of melt-spun Sm(Fe11Ti) 

      COEY, JOHN MICHAEL DAVID (IEEE, 1990)
      Hysteresis loops of randomly oriented grains with uniaxial anisotropy were computed on the basis of an array of 27 Wigner-Seitz cells representing crystallites which interact by exchange coupling at the grain boundaries. ...

    • Comment on the giant quadrupole interaction in EuxRhB. 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 1986)

    • Comparison between the amorphous and crystalline (A15) phases of Nb3Ge 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 1978)
      A comparative study on the superconducting and the normal-state properties of the amorphous, low-Tc (3.9 K) and the crystalline, high-Tc (2.18 K) phases of Nb3Ge suggests that changes in the strength of electron-phonon ...

    • Critical behavior of La0.75Sr0.25MnO3 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 2002)
      Magnetization, susceptibility, and specific heat measurements were made on a single crystal of La0.75Sr0.25MnO3. The ferromagnetic-to-paramagnetic phase transition was found at 346 K and four critical exponents were measured ...

    • Crystal Fields in Nd2Fe14B 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 1984)
      The leading terms in the crystal field at both rare-earth sites in the new permanent magnet alloy Nd2Fe14B are B20 and B22s. The sign of B20 explains the variation of the anisotropy constant K1 reported by Sagawa et al. ...

    • Current trends in amorphous magnetism 

      COEY, JOHN MICHAEL DAVID (IEEE, 1984)
      Recent research on some topics in amorphous magnetism is reviewed and questions are posed which should be answered by future work. The topics are i) appearance of magnetism in binary alloys of the 3d transition elements ...

    • Domain-wall dynamics in aligned bound Sm2Fe17 

      COEY, JOHN MICHAEL DAVID (American Physical Society, 1996)
      ac susceptibility (?ac=??-j??) of an aligned bound Sm2Fe17 powder sample has been measured along the easy direction as a function of temperature, frequency, warming rate, and time. Anomalous behavior has been found in that ...