High conductivity of mixed phase Al-substituted Li7La3Zr2O12

Al-substituted Li7La3Zr2O12 (LLZ:Al) was synthesized via conventional solid state reaction. Different dwell times at sintering temperature of 1200 °C led to a varying Li content in LLZ:Al which significantly affected the Li-ion conductivity. Electrochemical impedance spectroscopy and X-ray diffraction were used to characterize the sintered pellets which showed a maximum total ionic conductivity of ~3 × 10−4 S cm−1 at room temperature although the samples were composed of cubic and tetragonal LLZ:Al, with the tetragonal phase as its major phase. Inductively coupled plasma optical emission spectroscopy revealed that the Li content steadily decreased from 7.5 to 6.5 Li per formula unit with increasing sintering time. The highest conductivity was observed from the sample with the lowest Li concentration at 6.5 per formula unit. Scanning electron microscopy images revealed the formation of large grains, about 500 μm in diameter, which additionally could be the reason for achieving high total Li-ion conductivity. Electrochemical tests showed that mixed phase LLZ:Al is stable against metallic Li up to 8 V

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This chapter describes lasers and other sources of coherent light that operate in a wide wavelength range. First, the general principles for the generation of coherent continuous-wave and pulsed radiation are treated including the interaction of radiation with matter, the properties of optical resonators and their modes as well as such processes as Q-switching and mode-locking. The general introduction is followed by sections on numerous types of lasers, the emphasis being on todayʼs most important sources of coherent light, in particular on solid-state lasers and several types of gas lasers. An important part of the chapter is devoted to the generation of coherent radiation by nonlinear processes with optical parametric oscillators, difference- and sum-frequency generation, and high-order harmonics. Radiation in the extended ultraviolet (EUV) and x-ray ranges can be generated by free electron lasers (FEL) and advanced x-ray sources. Ultrahigh light intensities up to 1021 W/cm2 open the door to studies of relativistic laser–matter interaction and laser particle acceleration. The chapter closes with a section on laser stabilization