Direct experimental evidence of half-metallic density of states (DOS) is observed by scanning tunneling spectroscopy on ferromagnetic La0.7Ca0.3MnO3, which exhibits colossal magnetoresistance (CMR). Tunneling conductance data taken at 77 K, well below the Curie temperature TC ø 260 K, show close resemblance to the spin-split DOS spectrum calculated for the itinerant bands in the ferromagnetic s...

The phonon density-of-states ~DOS! of elemental vanadium was measured at elevated temperatures by inelastic neutron scattering. The phonon softening predicted by thermal expansion against the bulk modulus is much larger than the measured shifts in phonon energies. We conclude that the phonon anharmonicities associated with thermal expansion are largely canceled by effects from phonon-phonon sca...

Resonant photoemission spectra of the O 2p-derived valence band of insulating ThO2 are compared to linear muffin-tin orbital (LMTO) density-of-state (DOS) and XPS intensity calculations. At Th 5d corelevel threshold energies (85 ~< hv <<. 120eV), resonance is greatest at the bottom of the O 2p band where calculated p/d hybrid states are greatest; p / f hybrid content is weak by comparison. We c...

Under the generalized coherent-potential approximation, we established a "quasimode" theory to study the effective-medium properties of electromagnetic metamaterials. With this theory, we calculate the self-energy, density of states (DOS), and mean-free paths for optical modes traveling inside a metamaterial, and then determine the effective permittivity and permeability of the metamaterial by ...

We report measurements of the tunneling density of states (DOS) of ultrathin Al films in which superconductivity is quenched by a parallel magnetic field, Hk . 48 kG. The normal state DOS not only displays the usual logarithmic zero bias anomaly (ZBA) but also a new anomaly, superimposed on the ZBA, that appears at bias voltages V , 2mBHkye, the electron Zeeman splitting. Measurements in tilted...

We developed a fabrication technique of very thin silicon nanowall structures. The minimum width of the fabricated silicon nanowall structures was about 3 nm. This thinnest region of the silicon nanowall structures was investigated by using cathode luminescence and ultraviolet photoelectron spectroscopy (UPS). The UPS measurements revealed that the density of states (DOS) of the thinnest region...

We calculate the tunneling density of states (DOS) of MgB2 for different tunneling directions, by directly solving the real-axis, two-band Eliashberg equations (EE). Then we show that the numeric inversion of the standard singleband EE, if applied to the DOS of the two-band superconductor MgB2, may lead to wrong estimates of the strength of certain phonon branches (e.g. the E2g) in the extracte...

Ca 2p-3d resonant photoemission spectroscopy of a Cd6Ca crystalline approximant unambiguously demonstrates that the low-lying unoccupied 3d levels of calcium are lowered below the Fermi energy by the formation of the approximant, as suggested from electronic structure calculations [Phys. Rev. Lett. 87, 206408 (2001)]]. Moreover, the Ca 3d partial density of states (DOS) obtained near the Fermi ...

Warping of energy bands can affect the density of states (DOS) in ways that can be large or subtle. Despite their potential for significant practical impacts on materials properties, these effects have not been rigorously demonstrated previously. Here we rectify this using an angular effective mass formalism that we have developed. To clarify the often confusing terminology in this field, "band...