2 research outputs found
Cyclic Phase Transition from Hexagonal to Orthorhombic Then Back to Hexagonal of EuF<sub>3</sub> While Loading Uniaxial Pressure and under High Temperature
The structure and
photoluminescence properties are investigated
under high pressure and high temperature for pure orthorhombic and
hexagonal EuF<sub>3</sub> nanocrystals. Under hydrostatic compression,
the hexagonal EuF<sub>3</sub> remains stable at pressures up to 26
GPa. Under nonhydrostatic compression, a cyclic phase transition from
hexagonal to orthorhombic and then back to hexagonal is observed for
the first time. When loading uniaxial compression, the pure hexagonal
EuF<sub>3</sub> partly transforms to orthorhombic at 70 MPa, then
the orthorhombic EuF<sub>3</sub> transforms to hexagonal at about
3 GPa, and the transition is completed at about 10 GPa. The cyclic
phase transition is also observed during the heating process; the
hexagonal transforms to orthorhombic at 550 °C and then to hexagonal
at 855 °C. The content phase diagrams are obtained under high
pressure and at high temperature
Experimental Determination of the Rotational Constants of High-Lying Vibrational Levels of Ultracold Cs<sub>2</sub> in the 0<sub>g</sub><sup>–</sup> Purely Long-Range State
We
report on a quantitative experimental determination of the rotational
constants for the high-lying vibrational levels of the ultracold pure
long-range Cesium molecules formed via photoassociation. The scheme
relies on a precise reference of frequency difference in a double
photoassociation spectroscopy, which is induced by two laser beams
based on an acoustic-optical modulator. The rotational constants are
obtained by fitting a nonrigid rotor model into the frequency intervals
of the neighboring rotational levels deduced from the reference