Phase stability analysis of shocked ammonium dihydrogen phosphate by X-ray and Raman scattering studies

Impact of shock waves on non-linear optical materials bring about a lot of unknown behaviors of materials and such kinds of shock wave recovery experiments are highly required for the better understanding of material-property relationship. In the present context, we have performed experiments on the impact of structural properties of ammonium dihydrogen phosphate (ADP) samples under shock wave loaded conditions and the results of the test samples have been evaluated by X-ray diffraction (XRD), Raman spectroscopy, diffused reflectance spectroscopy (DRS) and field emission scanning electron microscopic (FESEM) technique. Interestingly, prismatic face of ADP shows loss of degree of crystallinity whereas pyramidal face shows enhancement of crystalline nature with respect to number of shock pulses due to shock wave induced dynamic re-crystallization. Hence, the present problem is worthy enough to unearth and understand the anisotropic nature of the ADP crystal and their structural modifications at shock wave loaded conditions.

Study on defect-induced damage behaviors of ADP crystals by 355 nm pulsed laser

High-quality ammonium dihydrogen phosphate (NH₄H₂PO₄, ADP) crystals were grown in Z direction and in defined crystallographic direction (θ=90°, φ=45°) by the rapid growth method, respectively. Defect-induced damage behavior in 355 nm of three types of ADP samples cutting in type-II matching and third harmonic generation direction from the as-grown crystals were investigated, including the initial laser induced damage (LID) characteristics and the physical and chemical properties of defects which serve as the damage precursors. The evaluations of damage behaviors include the "sampling" laser induced damage threshold (LIDT) by 1-on-1 and R-on-1 methods, bulk damage growth and bulk damage morphology. UV-visible transmittance spectrum, ultraviolet absorption spectrum, fluorescence spectrum, positron annihilation spectrum and the online light scattering measurements were carried out to investigate the defect-induced damage behavior in ADP crystals. The study will provide a reference for the investigations on laser induced damage properties of ADP crystals in short wavelength.

The effects of deuteration-levels in solution and temperature on the segregation coefficient of the deuterium content in rapid-grown K(DxH1−x)2PO4 crystals via Raman spectroscopy

The correlation between the deuterium segregation coefficient and temperature, and the deuterium content in a solution was studied for the first time.