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Fe(3)O(4)@C microcapsules were prepared using carbon-coated α-FeOOH nanorods as precursors, which were synthesized via two-step hydrothermal reactions. During the subsequent sintering procedure, α-FeOOH was reduced to Fe(3)O(4) by carbon, accompanied by the formation of mesopores. In Fe(3)O(4)@C microcapsules, mesoporous Fe(3)O(4) nanorods are coated with amorphorous carbon layers. The Fe(3)O(4)/C composites with such special structures demonstrate high specific capacity and good cyclic stability as anode materials in Li test cells.

Bi-doped BaF(2) crystal was grown by the temperature gradient technique and its spectral properties were investigated. The absorption, emission and excitation spectra were measured at room temperature. Two broadband emissions centered at 1070 and 1500 nm were observed in Bi-doped BaF(2) crystal. This extraordinary luminescence should be ascribed to Bi-related centers at distinct sites. We suggest Bi(2+) or Bi(+) centers adjacent to F vacancy defects are the origins of the observed NIR emissions.

The solid solution of (1-x)BiFeO3-xDyFeO3 was prepared by solid state reactions in the form of ceramics. The effects of chemical modification by means of aliovalent ionic substitution of Ti4+ for Fe3+ on the structure and dielectric properties were investigated. A morphotropic phase boundary bridging the perovskite rhombohedral phase and the orthoferrite orthorhombic phase was identified at x around 0.1. The chemical modification was found to stabilize the perovsite phase. The dielectric performance of the solid solution was improved by the substitution of Ti4+ for Fe3+, which decreased the electric conductivity by reducing oxygen vacancies, as evidenced by the decrease in loss tangent values. Magnetic hysteresis and large saturated magnetization (0.5 μB/f.u.) were realized in 0.92BiFeO3-0.08DyFeO3 with 2% substitution of Ti4+ for Fe3+, which is believed to arise from the disruption of the spiral spin modulation after structural modification, and the interaction between the spins of the Dy3+ and Fe3+ at low temperatures which decouples the antiferromagnetic order between the Fe3+ ions. [ABSTRACT FROM AUTHOR]

A bulk crystal of Yb:Sc2SiO5 (Yb:SSO) with favorable thermal properties was successfully obtained by the Czochralski method. The energy level diagrams for Yb:SSO crystal were determined by optical spectroscopic analysis and semi-empirical crystal-field calculations using the simple overlap model. The full width at half maximum of the absorption band centering at 976 nm was calculated to be 24 nm with a peak absorption cross-section of 9.2×10-21 cm2. The largest ground-state splitting of Yb3+ ions is up to 1027 cm-1 in a SSO crystal host. Efficient diode-pumped laser performance of Yb:SSO was primarily demonstrated with a slope efficiency of 45% and output power of 3.55 W. [ABSTRACT FROM AUTHOR]

A bulk crystal of Yb:Sc2SiO5 (Yb:SSO) with favorable thermal properties was successfully obtained by the Czochralski method. The energy level diagrams for Yb:SSO crystal were determined by optical spectroscopic analysis and semi-empirical crystal-field calculations using the simple overlap model. The full width at half maximum of the absorption band centering at 976 nm was calculated to be 24 nm with a peak absorption cross-section of 9.2×10-21 cm2. The largest ground-state splitting of Yb3+ ions is up to 1027 cm-1 in a SSO crystal host. Efficient diode-pumped laser performance of Yb:SSO was primarily demonstrated with a slope efficiency of 45% and output power of 3.55 W. [ABSTRACT FROM AUTHOR]