Squeezed-Out Technique To Prepare High-Quality PbBr-Based Layered Perovskite Langmuir-Blodgett Films Applicable to Cavity Polariton Devices.

We propose a promising preparation technique to construct optically high-quality Langmuir-Blodgett (LB) films of lead bromide-based layered perovskites having an organic-inorganic quantum-well structure called "squeezed-out technique." Using this technique, we successfully prepared PbBr-based layered perovskite LB films whose average roughness is small enough to apply them for cavity polariton devices. The small roughness reveals that one can prepare microcavities having a high quality factor by using the technique.

Thermoluminescence of coral skeletons: a high-sensitivity proxy of diagenetic alteration of aragonite.

Diagenetic alteration of aragonite coral skeletons causes changes in their chemical and isotopic compositions. Such altered coral samples are unsuitable for age dating or paleoclimate reconstructions. Recently developed microanalysis techniques have elucidated secondary aragonite precipitation and calcite overgrowth on primary aragonitic coral skeletons, but an effective screening method for bulk samples is still desirable.