D. E. Moncton

Antiferromagnetism in La 2 CuO 4 − y

Powder neutron diffraction studies of undoped

A new family of ternary intermetallic superconducting/magnetic stannides

{\mathrm{La}}_{2}

Spin slips and lattice modulations in holmium: A magnetic x-ray scattering study

{\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathrm{y}}

Intense Superradiant X Rays from a Compact Source Using a Nanocathode Array and Emittance Exchange

have revealed new superlattice peaks below \ensuremath{\sim}220 K. The absence of corresponding x-ray superlattice lines and an observed susceptibility anomaly near 220 K suggest the occurrence of antiferromagnetism. From the magnetic peak intensities we deduce a structure consisting of ferromagnetic sheets of Cu spins alternating along the [100] orthorhombic axis, with the spins aligned along the [001] orthorhombic axis, The low-temperature magnetic moment is approximately 0.5

Direct observation of long range ferromagnetic order in the reentrant superconductor HoMo6S8

{\mathrm{\ensuremath{\mu}}}_{\mathrm{B}}

DIFFRACTION STUDIES OF RARE EARTH METALS AND SUPERLATTICES

/(Cu atom). The tetragonal-orthorhombic transition at 505 K has also been studied.

Phase diagram and phase transitions of krypton on graphite in the extended monolayer regime

Abstract A new family of rare earth-rhodium-tin intermetallic compounds, with the representative formula (RE)Rh x Sn y , has been synthesized in single crystal form. The compounds containing the heavier rare earths are superconducting and those with the lighter rare earths are generally magnetic. The compound ErRh 1.1 Sn 3.6 exhibits reentrant superconductivity with T c = 0.97 K and T m = 0.57 K as determined from ac magnetic susceptibility measurements. The synthesis and X-ray characterization of the series are described and the results of electrical resistivity, upper critical magnetic field, magnetic susceptibility, specific heat and neutron scattering measurements on the Er compound are given.

Compact x-ray source based on burst-mode inverse Compton scattering at 100 kHz

Nearly all the microscopically small devices that are contributing to the “microtechnological” revolution are composed of thin layers of materials. Such devices are nearly two‐dimensional, and many of the questions concerning the ultimate possibilities and limitations of the technology will require investigation of the physical processes in two dimensions. Similarly, questions that arise in such diverse fields as surface physics, membrane biology and catalytic chemistry involve two‐dimensional phenomena. At least as important as these practical questions is simple intellectural curiously: How does Nature behave in a world of limited dimensionality?

Neutron scattering observations on the magnetic phases of rare‐earth ternary superconductors

The analysis of data obtained in magnetic X-ray scattering experiments on rare earth metals, particularly holmium, has led to a phenomenological model for one-dimensional spatially propagating magnetic structures. Based on the concept of spin slips or discommensurations, this model explains the observed lock-in transitions in the magnetic spirals of the rare earths in terms of simple commensurate structures. Further, the anomalous intensities of previously observed higher harmonic magnetic satellites, as well as the qualitative behavior of the magnetic wave vector in the presence of a magnetic field, are understood directly within the spin slip description. We discuss how the presence of spin slips in the magnetic structure can lead to modulations of the crystal lattice as demonstrated by a recent magnetic X-ray study of holmium.