27 Result(s)

Article

Effect of He Pressure on the Superconducting Transition Temperatures of Na₂CsC₆₀ and (NH₃)₄Na₂CsC₆₀

The Na based mixed alkali doped C₆₀ superconductors show anomalous behavior with respect to the “universal” superconducting transition temperature T_c vs lattice constant ao relation followed by most of the fee A₃

J. E. Schirber, W. R. Bayless, M. J. Rosseinsky, O. Zhou… in MRS Online Proceedings Library (1994)

Article

The Effect of O₂ Intercalation on the Rotational Dynamics and the Ordering Transition of C₆₀

We have used ¹³C magic-angle spinning (MAS) nuclear magnetic resonance (NMR) to characterize the structure and rotational dynamics of C₆₀ containing oxygen molecules located in the interstitial sites of the fee l...

S. A. Myers, R. A. Assink, J. E. Schirber, D. A. Loy in MRS Online Proceedings Library (1994)

Article

Stoichiometrically controlled direct solid-state synthesis of C₆₀H₂

The direct solid-state synthesis of C₆₀H₂ has been demonstrated by controlling the amount of hydrogen introduced into the reaction with C₆₀. Palladium hydride has been used as the source of hydrogen. The main pro...

B. Morosin, C. Henderson, J. E. Schirber in Applied Physics A (1994)

Chapter and Conference Paper

The Phase Diagrams and Doped-Hole Segregation in La₂CuO_4+δ and La_2−xSr_xCuO_4+δ (x ≤ 0.15, δ ≤ 0.12)

The magnetic and structural phase diagrams of the title systems are reviewed, with an emphasis on our recent results obtained from magnetic and structural neutron diffraction, thermogravimetric analysis, iodom...

D. C. Johnston, F. Borsa, P. C. Canfield… in Phase Separation in Cuprate Superconductors (1994)

Chapter and Conference Paper

Microscopic Study of Local Structure and Charge Distribution in Metallic La₂CuO_4+δ

We employ NMR and NQR spectroscopy as probes of local structure and charge environments in metallic La₂CuO_4+δ (T_c = 38 K). We discuss the effect of annealing the sample at various temperatures T ...

P. C. Hammel, A. P. Reyes, E. T. Ahrens… in Phase Separation in Cuprate Superconductors (1994)

Article

Strained quantum well modulation-doped ingasb/algasb structures grown by molecular beam epitaxy

Strained single quantum well InGaSb/AlGaSb structures for field-effect transistor applications have been grown by molecular beam epitaxy. Modulation-doped p-type structures have been characterized by a variety...

J. F. Klem, J. A. Lott, J. E. Schirber, S. R. Kurtz… in Journal of Electronic Materials (1993)

Article

Syntheses and Properties of k-Phase Organic Superconductors

The syntheses and physical properties of K-(ET)₂CU[N(CN)₂]X (X = Br and Cl) are summarized. The K-(ET)₂Cu [N(CN)₂] Br salt is the highest T_c radical-cation based ambient pressure organic superconductor (T_c = 11.6...

H. Hau Wang, K. D. Carlson, U. Geiser, A. M. Kini… in MRS Online Proceedings Library (1992)

Article

Thermal Desorption Studies of Isotopically-Labeled Oxygen from La₂CuO_4+δ

Isotopically-labeled oxygen enrichment and thermal desorption mass spectroscopy (TDMS) have been combined to study interstitial oxygen desorption from superconducting La₂CuO_4+δ(δ ≤ 0.032). Single crystal samples ...

N. D. Shinn, M. E. Bartram, J. E. Schirber… in MRS Online Proceedings Library (1990)

Article

Search for cold fusion at D/Pd > 1 using ion implantation

Deuterium was introduced into palladium at atomic ratios greater than one by means of ion implantation at cryogenic temperatures, and a search was made for energetic charged particles from D-D nuclear reaction...

S. M. Myers, D. M. Follstaedt, J. E. Schirber, P. M. Richards in Journal of Fusion Energy (1990)

Article

Correlation between photoluminescence data and device performance of p-channel strained-layer materials

The 4-K photoluminescence spectrum and room temperature transconductance for modulation dopedp-type GaAs/(In,Ga)As dual-channel strained-quantum-well field-effect transistors with comparable dopant and 2-D carrie...

E. D. Jones, T. E. Zipperian, S. K. Lyo, J. E. Schirber… in Journal of Electronic Materials (1990)

Chapter

Pressure in the Study of Organic Superconductors

There is probably no area in materials science where pressure has had such a profound effect upon the field as in the study of organic superconductivity. The initial discovery of superconductivity at <1.6K in ...

J. E. Schirber, H. H. Wang, J. M. Williams in Organic Superconductivity (1990)

Chapter

D

The de Haas-van Alphen effect is the periodic oscillation of the magnetization with inverse magnetic field. These oscillations were discovered in 1930 in Bi at very low temperature by W. J. de Haas and P. M. v...

J. E. Schirber, Robert G. Fuller, Richard M. Fuller… in The Encyclopedia of Physics (1990)

Article

Structural Aspects of the Phase Separation in La₂CuO_4.032

The average structure of superconducting La₂CuO_4.032 has been determined by single crystal neutron diffraction data. The excess oxygen is located between two adjacent LaO layers. Its presence distorts the apical-...

C. Chailloutl, P. Bordetl, J. Chenavasl, S. W. Cheong… in MRS Online Proceedings Library (1989)

Article

Annealing and Strain Effects on Tl-Ba-Ca-Cu-O Crystals and Ceramics

Superconducting transition temperatures (T_c’S) in the Tl-Ba-Ca-Cu-O system are shown to be a function of processing for both single crystals and bulk ceramics. Crystals with the identical structural phase and nom...

E. L. Venturini, B. Morosin, D. S. Ginley, J. F. Kwak… in MRS Online Proceedings Library (1989)

Article

Cation Disordering in the Tl-2122 Superconductors

We have examined several crystals belonging to the Tl-2122 structure type (Tl₂CaBa₂Cu₂O₈ with c=29Å), and have shown that cation solid solution occurs. Such cation disorder appears to be responsible for the obser...

B. Morosin, D. S. Ginley, E. L. Venturini, R. J. Baughman… in MRS Online Proceedings Library (1989)

Article

Material characterization of an ion-implantation process for p-type (InGa)As/GaAs quantum-well structures

We have performed a detailed study of the formation of Be⁺-implanted contacts to modulation-doped, p-channel, (InGa)As/GaAs, single-strained quantum wells. Photoluminescence at 4 K from these structures is shown ...

D. R. Myers, E. D. Jones, I. J. Fritz, L. R. Dawson… in Journal of Electronic Materials (1989)

Article

Energy Loss Rates for Light Holes in InGaAs/GaAs Strained-Layer Single Quantum Wells

Energy relaxation rates for light holes in InGaAs/GaAs strained layer quantum wells are measured. Two techniques were used to measure light hole temperatures as a function of power dissipated in the hole gas. ...

M. C. Smith, E. D. Jones, I. J. Fritz, T. J. Drummond… in MRS Online Proceedings Library (1987)

Article

Bulk Superconductivity in La₂CuO₄

J. E. Schirber, E. L. Venturini, B. Morosin, J. F. Kwak… in MRS Online Proceedings Library (1987)

Article

Variation of the pressure dependence of the superconducting transition temperature with x in La_1−xSr_x CuO₄

Hydrostatic pressure measurements of the superconducting transition temperature were made as a function of x in La_2−xSr_x CuO₄. A sharp change in the behavior occurs between x = 0.2 and 0.25 in that the pressure d...

J. E. Schirber, E. L. Venturini, J. F. Kwak, D. S. Ginley… in Journal of Materials Research (1987)

Article

Direct Observation of Valence-Band Mixing in GaAs/GaPAs Strained-Layer Superlattices

Low-temperature magneto-luminescence studies are used to examine the in-plane valence-band dispersion in GaAs/GaPAs strained-layer-superlattice structures. The results provide a direct observation of valence-b...

E. D. Jones, R. M. Biefeld, I. J. Fritz, P. L. Gourley… in MRS Online Proceedings Library (1986)