A light-transmitting compound called (A)ZrPSe 6, where A can be potassium, rubidium, or cesium, has a difficult chemical structure that does not crystallize well. Scientists from the Argonne National Laboratory and Northwestern University were able to determine the structure of the compound using the uniquely suited Chemistry and Materials (ChemMatCARS) beamline of the Center for Advanced Radiation Sources at the Advanced Photon Source. The material could one day be used in high-efficiency fiber optics and sensors that detect biological and chemical weapons at long distance.
"This material has an electrically polarized structure," said Argonne scientist Mercouri Kanatzidis. "The incident light interacts with the electron cloud and in the process is disturbed. The disturbance changes the wavelength of the emitted light and creates two beams: the original and the second harmonic - a beam with half the wavelength and double the frequency." This second-harmonic beam is 15 times more intense than that produced by the best current material. This wavelength boost is paired with greater transparency, so the material can transmit the whole higher-wavelength beam.