Reversible phase transition in laser-shocked 3Y-TZP ceramics observed via nanosecond time-resolved X-ray diffraction

The high-pressure phase stability of the metastable tetragonal zirconia is still under debate. The transition dynamics of shocked Y2O3 (3 mol%) stabilized tetragonal zirconia ceramics under laser-shock compression has been directly studied using nanosecond time-resolved X-ray diffraction. The martensitic phase transformation to the monoclinic phase, which is the stable phase for pure zirconia at ambient pressure and room temperature, has been observed during compression at 5 GPa within 20 ns without any intermediates. This monoclinic phase reverts back to the tetragonal phase during pressure release. The results imply that the stabilization effect due to addition of Y2O3 is negated by the shear stress under compression.Comment: 11 pages, 4 figures, draf

Structural Dynamics of Materials under Shock Compression Investigated with Synchrotron Radiation

Characterizing material dynamics in non-equilibrium states is a current challenge in material and physical sciences. Combining laser and X-ray pulse sources enables the material dynamics in non-equilibrium conditions to be directly monitored. In this article, we review our nanosecond time-resolved X-ray diffraction studies with 100-ps X-ray pulses from synchrotron radiation concerning the dynamics of structural phase transitions in non-equilibrium high-pressure conditions induced by laser shock compression. The time evolution of structural deformation of single crystals, polycrystals, and glass materials was investigated. In a single crystal of cadmium sulfide, the expected phase transition was not induced within 10 ns at a peak pressure of 3.92 GPa, and an over-compressed structure was formed. In a polycrystalline sample of Y2O3 stabilized tetragonal zirconia, reversible phase transitions between tetragonal and monoclinic phases occur within 20 ns under laser-induced compression and release processes at a peak pressure of 9.8 GPa. In polycrystalline bismuth, a sudden transition from Bi-I to Bi-V phase occurs within approximately 5 ns at 11 GPa, and sequential V–III–II–I phase transitions occur within 30 ns during the pressure release process. In fused silica shocked at 3.5 GPa, an intermediate-range structural change in the nonlinear elastic region was observed

Transportation of Nano/Microparticles via Photoinduced Crawling of Azobenzene Crystals

Abstract The stimulus‐driven motion of microscale objects on solid surfaces is a promising process to realize the manipulation of microdroplets, which has applications in fields areas such as material accumulation and sensing at a micro level. Light is an effective external stimulus for object manipulation because it can provide contactless spatial and temporal control. In this study, a new method is devised to transport nano/micromaterials on a glass surface by exploiting the photoinduced crawling motion of crystals. 4‐(methylamino)azobenzene (4‐MAAB) crystals are used to transport nano/micromaterials via photoirradiation from a single visible‐light source without using expensive equipment such as lasers and positioning devices. Nano/micromaterials mixed with the 4‐MAAB crystals are successfully transported with the crawling 4‐MAAB crystals. The nano/micromaterial transport is tracked using the fluorescence from the nano/micromaterials embedded into the 4‐MAAB crystals. In situ time‐resolved X‐ray diffraction measurements are also conducted for mechanistic analysis. This study offers new development paths in fields such as microfluidics and microrobotics

Structural investigation of the photoinduced spin transition in the [Fe(PM-BIA)2(NCS)2] compound

We investigated the thermo- and photo-induced phase transitions between low spin (LS) and high spin (HS) states of the mol. crystal of [Fe(PM-BiA)2(NCS)2] in the orthorhombic form, by using X-ray diffraction. The structure of the photoinduced HS state, generated from the LS state at low temp., is compared to the structures of the HS and LS phases at thermal equil. and to the thermally trapped HS state. The preliminary results presented here show that the structural reorganization is similar in the different HS states