— Reflectivity, fluorescence and photoelectron spectra from CaF2 single crystals hâve been measured using synchrotron radiation in the 10 to 100 eV range. The spectra contain features ascribed to excitons and to the band structure. Peaks due to conduction-band states derived from the 3d atomic levels are prominent in ail three

The binary phase diagram CaF2–SrF2 was investigated by differential thermal analysis (DTA). Both substances show unlimited mutual solubility. An azeotropic point showing a minimum melting temperature of Tmin = 1373 C for the composition Ca0.582Sr0.418F2. Close to this composition, homogeneous single crystals up to 30mm diameter without remarkable segregation could be grown by the Czochralski me...

Electron transfer processes between lanthanide activators are crucial for the functional behavior and performance of luminescent materials. Here, a multiconfigurational ab initio study reveals how direct metal-to-metal charge (MMCT) Eu2+ luminescence activator Ln3+ co-dopant (Ln3+ = Ce3+, Pr3+, Nd3+, Pm3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+) systematically dictates optical pro...

Absorption, photoluminescence spectra and cw lasing parameters of an Yband Na-codoped CaF2 laser crystal are measured in the temperature range from 5 K to 290 K. The crystal appears to be a promising host for broadband multi-mJ kHz cw-pumped regenerative amplification.

The human pathogen Candida albicans encodes at least three putative two-component histidine kinase signal transduction proteins, including Chk1p and a response regulator protein (Cssk1p). Strains deleted in CHK1 are avirulent in a murine model of hematogenously disseminated disease. The specific function of Chk1p has not been established, but hyphae of the chk1 mutant exhibit extensive floccula...