Showing papers by "Sheldon Schultz published in 1997"
117 citations
TL;DR: In this article, the authors have fabricated arrays of high aspect ratio nickel columns in both PMMA and SiO2, and characterized their structure using transmission electron microscopy and scanning electron microscope.
Abstract: We have fabricated arrays of high aspect ratio nickel columns in both PMMA and SiO2, and we have characterized their structure using transmission electron microscopy and scanning electron microscopy. We have also characterized the magnetics of the columns with magnetic force microscopy. Such characterization of high aspect ratio perpendicular magnetic particles is only rarely found in the literature. This work lays a foundation for further studies to test the viability of lithographically defined arrays of magnetic particles as an alternative high density storage medium.
74 citations
01 Apr 1997
TL;DR: In this paper, the magnetic field due to the bias current in the MR head was found to switch the columns during scanning, which results in a "dibit-like" MR response.
Abstract: We report, for the first time, the MR head response from lithographically patterned perpendicular nickel columns. Electron-beam lithography is used to fabricate arrays of Ni columns, 400 nm tall and 150 nm in diameter spaced 2.1 /spl mu/m apart, embedded in SiO/sub 2/. The sample surface is planarized with a chemical mechanical polish. The technique of Scanning Magnetoresistance Microscopy (SMRM), in which a magnetoresistive (MR) head is raster-scanned in contact with a sample, is used to investigate the MR head response from the Ni columns. Single columns can be "read" with a 0-peak MR voltage of 60-70 /spl mu/V. Unexpectedly, we find that the magnetic field due to the bias current in the MR head is enough to switch the columns during scanning, which results in a "dibit-like" MR response, By scanning in the presence of a small (/spl sim/21 Oe) external magnetic bias field, the columns can be imaged in either their "up" or "down" magnetic states.
16 citations
TL;DR: In this article, the superconducting critical temperature (Tc) varies with the stoichiometry, showing the highest Tc for a Y/Ni ratio of 1/2, attributed to the YNi2B2C phase.
Abstract: We have searched for superconductivity in a wide variety of stoichiometries in the Y-Ni-B-C system, using Yx(NiB)Cy phase spread alloy thin films and the magnetic field modulated microwave absorption technique. The superconducting critical temperature (Tc) varies with the stoichiometry, showing the highest Tc for a Y/Ni ratio of 1/2, attributed to the YNi2B2C phase. We found no other superconducting phases with a Tc higher than 10 K. Furthermore, a search in YxNiB(C1−zNz)y and YxNiBNy phase spread alloys showed no superconductivity.
7 citations
TL;DR: In this paper, the Schottky barrier of a heavily doped Si layer covered with a metal film is investigated using conduction electron spin resonance, which is utilized in situ in UHV to continuously monitor the metal overlayer development from a fractional monolayer through multiple layers.
Abstract: The Schottky barrier of a heavily doped Si layer covered with a metal film is investigated using conduction electron spin resonance, which is utilized in situ in UHV to continuously monitor the metal overlayer development from a fractional monolayer through multiple layers. Measured increases in linewidth are compared with calculations based on a kinetic theory. For Al and Ag, the data can be explained both by flat-surface and island models, even though for Al only a flat-surface model with smooth surfaces is compatible with the experiments. In contrast, for Cu and Al-Cu bilayers, the data unambiguously favor the rough-surface island model.
5 citations